Check & Troubleshooting of Products
In The Name of God
The best service of Hekmat industrial system:
– Technical consultation in the field of hydraulic fittings
– Send out hydraulic engineers to all parts of the country
Wired hydraulic hose
Wired hydraulic hose has different models that include1 layer wire, 2 layers wire, 4 layers wire and 6layers wire. There are just 1 layer wire and 2 layers wire in sizes 3/16, 1/4 and 5/16 and there are only 1 layer wire, 2 layers wire and 4 layers wire in sizes 3/4, 5/8, 1/2 and 3/8, and in sizes 1″, 11/4, 11/2 and 2″ there are only 1 layer wire, 2 layers wire, 4 layers wire, 6 layers wire and also in sizes 21/2, 3″ and 4″ there are 1 layer wire, 2 layers wire and 4 layers wire. Of course you should know larged- sized wired hose (21/2, 3″, 4″) are not continuously in Iran and you should check before hydraulic design and organize.
Hekmat industrial system supply all the wired hoses with pressured guarantee, even if hoses are cut by the costumers’ orders and pressed by valves.
Costumers could return all the products until 30 days after buying them if they were not according to your orders and if the products were not according to global standards or they had mechanical wrongs it is possible for you to return them each time for ever.
Teflon hydraulic hoses
They are 4 kinds:
1-Cotton covered Teflon hoses:
They are made of one layer inner Teflon and cotton of best quality and one layer rubber and there are 1/8, 3/16, 1/4, 5/16, 3/8, 1/2, 5/8, 3/4, 1”, 11/4, 11/2, 2″. There are colored cotton covered Teflon hoses in some sizes.
2-Wired Teflon hoses:
They are made of one layer inner Teflon, best quality of wires and one layer rubber. There are 1/4, 5/16, 3/8, 1/2, 5/8, 3/4.
3-Twin cotton covered Teflon:
There are in 1/4, 5/16, 3/8, 1/2, 5/8, 3/4 and 1″.
4-Twin wired Teflon hoses:
There are in sizes 5/8, 1/2, 3/8, 5/16, 1/4.
Selling all wired Teflon and cotton covered Teflon hoses are guaranteed by Hekmat industrial system according to global standards and costumers could perform their projects according to global standards very relax.
Steam hoses:
There are in different kinds that include flexible hoses, steam Teflon hoses and steam hoses.
Steam flexible hoses are covered by steel straw because of protective and also they are in 2 proboscis models. One of them is spiral and the other is in ring shape. Steam flexible hoses could be only sealed by welding related series and also it must be used to Argon weld. There are in sizes 3/8, 1/2, 3/4, 1″, 11/4, 11/2, 2″, 21/2, 3″, 4″, 5″, 6″, 8″ and 10″.
Steam Teflon hoses are made of one layer Teflon Ptfe and one layer straw cover in sizes 3/16, 1/4, 5/16, 3/8, 1/2, 5/8, 3/4 and 1″. And the way of sealing of the steam Teflon hoses with their valves must be done by their hydraulic presses and it must be said that to press the steam Teflon hoses, special hydraulic shells must be used and the shells of the hydraulic hoses are not suitable and standard for it.
Steam hoses are in sizes 3/8, 1/2, 5/8, 3/4, 1″, 11/4, 11/2and 2″ and it made of one layer of fireproof rubber and no to inner heat, one layer middle wire and one layer outer fireproof rubber, also sealing of steam hoses must be with hydraulic hoses’ press, steam hoses also must be pressed by special steam shells to be more standard.
Costumers just pay attention that if you order your products of Hekmat industrial system, you would know production of hoses have done by our experienced engines and all fittings, hoses and valves are according to global standard and if costumers buy the goods that were not made they can return them until one month after billing of facture.
Information on hydraulic hoses
Hydraulic hoses are made from rubber layers or thermoplastic materials which are woven from Steel strip layers or woven fiber. These layers of hoses are made from single protective outer layers of rubber or plastic.
Multiple spiral hoses (or multi-layers):
Several spiral hoses (or multi-layers) are used for high pressure applications. Their structure is similar, but several spiral layers have been used in woven and resistant wire strips that are separated from each other by plastic layers.
Modern hoses:
Modern hoses have a smaller inner diameter and thermoplastic materials are used for the outer layers (inner coating) of woven fibers to reinforce the tube. These types of tubes are used more in the automotive industry.
Pressure: The pressure of the hose (in any one direction) depends on inner diameter in any cases.
Minimum burst pressure: Hose safety coefficients are high and the Minimal design pressure for burst is usually five times the working pressure.
Hose connection
Prescription binding (fixed):
In pressed connection, hoses are pressed into the connecting hubs by hydraulic or mechanical special press. A very simple tool is used in the detachable connection. Of course, the term detachable is not the correct name for this type of connection, because it rarely happens to be used more than once. Hose walls is placed between the inner and outer rings of the connecting head and pressed firmly after pressing, in pressed connection.
Detachable connection:
The detachable connection is used to create an accurate radius for the R1 and R2 hub Connection. In this method, after preparing the hose head, the outer ring of the hub is screwed onto the hose (the screw is rounded). Therefore, the hose walls packed like sandwich between the Inner and outer ring. For attaching rings, they lubrication with circuit oil.
It should chuck, skin, and turnery the head of some types of hoses before attach the inner rings. The outer ring placed directly onto the hose in non – cut or turnery hoses. A special prefabricated tool is required for fitting a detachable connection on thermo plastic pipes. These tools can also be used in conventional rubber hoses.
The hose and fitting have a very high variation. For each class of hose, more than 30 types of fittings are produced in different sizes for each of the two types of pression and detachable one. In a multi-layer hose, a press fitting should be used. In all types of fitting, it is recommended that at least one of the hoses on the fittings can be rotated.
The method of installing hydraulic hoses
In the installation of a hydraulic hose, the following points should be noted:
1- Avoid making sharp bends and curves in the hose. All fittings should be placed on one page.
2- Do not touch the hoses together or with metal parts.
3-Select one of the correct methods for installing hose fittings.
Manufacturers specify the minimum permitted bending radius and the minimum length of hoses in the catalog. More recommendable bends , reduce working pressure, hose useful life , and service time and repair. Sometimes, metal nets are used to control the bending radius of the hoses.
Hydraulic hose damage and rupture
A sudden hose’s rupture is possible. Specifying hose’s instruction date there is a number. Of course, predicting the actual life of a hose is very difficult because its depends on the type of application and environmental conditions. However, frequent faults in the hose may not be due to selection, connection, and installation. Recognizing these causes can significantly help to solve the problem. The hose manufacturer is the best person to be able to show signs of failure with their test devices.
In short, the hose and fitting must have the following properties:
1- Compatible with the circuit fluid.
2- Compatible with the system working pressure, the pressure level of the ram and the pressure and flow fluctuations.
3- Withstand tolerance of fluid and environmental temperatures.
4- Carefully selected (in size) to keep the pressure drop at a minimum and prevent the destruction caused by turbulence and heat generation.
5- Be sure to carefully check the correct connection of the hose. Make sure that special tools are used as needed and recommended by the manufacturer.
6-The method and procedure for installing the hose and joints shall be in a way to prevent the formation of sharp bends, bending, crushing, wear, torsion, vibration and elongation. Note that when the pressure inside the hose rises, its length will be reduced to 4%. The hose movement should be flexural not torsional.
Troubleshooting Hydraulic Systems
General Issues of Hydraulic Systems:
Lack of pressure
Lack of Dubai
Soaking the pump
Too much heat
The wrong actions of the operators
Rapid depreciation of parts
Seven Simple Steps to Troubleshoot Hydraulic Systems
Many defects in hydraulic systems have similar symptoms. For example, a gradual or sudden drop in pressure reduces the power or speed of the cylinder. Sometimes the hydraulic cylinder may stop at the load and do not move at all. Often the power loss will be accompanied by increased sound at the pump, especially at times when the system is pushed and this pressure is transferred to the pump. In troubleshooting of simple hydraulic systems, the main components of the pump, the pressure gauge, the direction control valve or the cylinder may be objectionable, and it is necessary to operate an experienced technician service. Using the step-by-step method, you can track the defects of the hydraulic system and, if necessary, test or modify the parts.
Step 1: Check the suction filter (filter)
Perhaps the first problem most often encountered in hydraulic systems is the cavitation phenomenon caused by the obstruction caused by foreign particles in the suction filter. This phenomenon may occur in old pumps or new pumps. Cavitation increases the volume and reduces pressure or speed. Usually the suction filter is immersed below the oil. The hydraulic system operator usually does not service it until it is installed in the system. Under such conditions, sooner or later the suction filter will be blocked and the entire hydraulic system will be stopped. Metal nets can be cleaned with air pressure. Oil can be used to clean the filters used in oil base oils. But never use gasoline. If the suction filter has been hit and tilted, replace it. When reinstalling the suction blade, check all connections to ensure that the air is not supplied. Oil at the bottom is at least 8 cm higher than the suction filter.
Step 2: Checking the pump and pressure breaker simultaneously
If the pump filter cleaning does not fix the fault, remove the pump and pressure breaker from the rest of the circuit. To do this, disconnect the valve output of the pressure switch connected to the feeder valve. In this way, only the pump, pressure breaker and pressure switch remain in the pump circuit. Block the output of the pressure switch with a cover. In this way, the entire pump is drained from the pressure switch to the reservoir. Turn the pump on and push the pressure regulator in the pressure gauge by tightening the pressure regulator.
If the system is not fully pressed, go to step three.
Step 3: Separate examination of the pump and pressure breaker
If the maximum optimum pressure is not obtained in the second step, then further tests on the pump and pressure breaker should be performed. If possible, disassemble the drain plug into the tank. Then attach a short hose to the output. Open the hose to the tank inlet so that you can see the flow rate from the tank entering it and turn on the pump and loosen and tighten the pressure regulator and adjust the amount of flow out of the breaker See If the pump runs badly, the output of the pressure cutter is fully depleted when the adjustment screw is completely loose, and with the closure the pump’s pump flow decreases. If a flow meter is available, then the pump output pump can be compared to the one mentioned in the catalog. If the flow meter is not available, small pumps can be used to calculate the discharge by draining the pump outlet oil into a bucket and measuring the time. For example, if 10 liters of oil were poured into the bucket in 15 seconds, it would dissolve 40 liters in 60 seconds or a minute. As a result, the pump is 40 liters per minute.
If the pressure gauge does not show a pressure greater than about 7 bar, or if the pump’s discharge is not reduced if the pressure relief valve is closed, the fault pressure must be dealt with in accordance with step five. (First, make sure the pressure gauge is healthy)
Step Four: Check the pump
If the full flow of the pump does not come out in step 3 or the flow decreases with the shut-off valve, it is likely that the pump will fail. Assuming that the suction line filter is clean and the sanitary piping is intact and the air does not enter the oil slides through the internal components of the pump. This indicates a worn pump or high temperature oil. The oil internal displacement on the pump makes the pump body temperature much hotter than the tank oil. In normal operation, a healthy pump, its shell temperature may be up to 10 ° above the reservoir temperature. If this temperature is too high, there is a possibility of internal oil leakage. There is also the possibility of loosening or slipping of transmission belts, cutting shafts or fittings, or the presence of loose screws in the transmission system.
Step Five: Check Pressure
If the third step indicates that the fault is in the breaker, the fastest step for defect detection is to replace the pressure switch with a healthy sample. Defective milk can be opened and checked later.
Pilot-pressure tumbler valves have a small aphid (orifice) that may be condensed by the waste material. Clean the compressed air or a thin piece of nicotine. Also check Spool free movement. In the pressure cutters in the pipe path, it is possible to collect spools due to the close fitting of the pipe and fittings.
Step 6: Check the cylinder
If the second stage is full of pressure in the system, the pump and pressure breaker are both healthy and the defect of the system may be at the bottom of the circuit.
The first step in this test is to test the faulty cylinder packs. To test, move the piston to one of the two ends of your course and stop it in the same position. Then open the piston connections and check the leakage of the oil. After checking, tighten the connection and move the piston to the opposite side and repeat the test. The latest test can also be repeated at the mid-point of the cylinder. Of course, to stop the cylinder, it is necessary to place a high-strength barrier in front of the piston. If there is leakage, the cylinder packing is defective and must be replaced.
Step 7: Check the flow valve
If the tested cylinder is healthy in step six, it is necessary to check the flow valve. Although it is usually less likely to occur, but a lot of abrasions in the milk spoil may prevent the pressure from forming in the system.
Tips on Hydraulic Systems
Hydraulic system
Today, in many industrial processes, power transmission is considered low cost and with high precision. In this regard, the use of pressure fluid in the transmission and control of power in all branches of the industry is expanding. The use of fluid power is divided into two major fields as hydraulic and pneumatic branches (which are newer). The use of a neuromatic system in cases where relatively low forces (about one ton) and high motor velocities are needed (such as those used in belt actuators) are used when the applications of hydraulic systems are mainly in those cases where high powers and velocities Controlled precision (such as hydraulic jacks, brakes and hydraulic steering, etc).
The question now is what are the benefits of a hydraulic or pneumatic system to other mechanical or electrical systems? The answer to this is the following:
1. Simple design 2. Power increase 3. Simple and precise control
4. Flexibility 5. High efficiency 6. Reliable
In hydraulic and pneumatic systems, there are fewer actuator parts than other mechanical systems, and high-power and high-speed linear or rotational movements can be achieved at any point, since power transmission by high-pressure fluid flows in transmission lines (tubes and Hoses are used, but in other mechanical systems they use components such as cam, gear, car, lever, clutch, and so on.
In these systems, it can be achieved by applying a low force to the high and precise force. Also, large output forces can be controlled by applying a small force (such as valve closing valves, etc.)
The use of flexible hoses turns hydraulics and pneumatics systems into flexible systems that do not mention the space constraints that are being used to install other systems. Hydraulic and pneumatic systems have high efficiency due to low friction and low cost. Also, using pressure relief valves and heat and pressure switches, a system resistant to sudden loads, heat or pressure can be made which indicates the high reliability of these systems has it. Now that we understand the advantages of hydraulic and pneumatic systems, we will give a simple explanation of how these systems work.
In order to transfer power to a pressurized (compressible or incompressible) fluid, it is possible that mechanical pumps can be converted to fluid pressure by hydraulic pumps. The next step is to transfer the force to the desired point, which assumes responsibility for pipes, hoses and fasteners.
After controlling the pressure and determining the flow direction by the valves, the fluid is guided by pressure to the operators (cylinders or hydraulic motors) to convert the fluid’s strength to the required mechanical force (linear or rotational ).
The basis of the work of all hydraulic and neuromatic systems is based on Pascal’s law.
Pascal’s Law:
1. The pressure across the stagnant fluid is the same ( regardless of the weight of the fluid )
2.At any given moment, the static pressure is the same in all directions.
3.The pressure of the fluid in contact with the surfaces is introduced vertically.
As you can see in Figure 1, a Newtonian input can provide the required four-cylinder power.
Figure(1)
Or in Figure 2:
Figure(2)
The act of the neuromatic systems is similar to that of hydraulic systems, only using compressible fluid such as air instead of an incompressible fluid such as oil. In neuromatic systems, to reach a high pressure fluid, compresses the air by a compressor to reach the desired pressure, then stores it in a reservoir, although the air temperature is very high after compression, which can damage the system parts. Therefore, compressed air must be cooled to the power transmission lines before conducting it. Due to the presence of water vapor in compressed air and the condensation phenomenon in the cooling process, an optimization unit should be used to dry the high pressure air.
Now, after a brief introduction of hydraulic and pneumatic systems act, we introduce the components of a hydraulic and pneumatic system.
Components of Hydraulic Systems:
1-Tank: to keep fluid
2. Pump: In order to flow fluid into the system that is powered by an electro-motor or
3- Internal combustion engines
4. Lids: To control the pressure, flow and direction of the fluid flow
5. Operators: To convert the energy of the fluid under pressure to the mechanical working force (hydraulic cylinders for linear motion and hydraulic motors for rotational motion)
Figure 3 shows a hydraulic system.
Figure (3)
Components of New Material Systems
1- Compressor
2- Cooling and drying pressurized air
3- Pressurized air reservoir
4- Control valves
5- operators
Figure 4 shows a neumatic system.
Figure 4
A Comparison between Hydraulic and Neumatic Systems:
1- In a new system, a compressible fluid, such as air, is used and in hydraulic systems it uses an incompressible fluid such as oil.
2- In hydraulic systems, oil, in addition to power transmission, also has the function of lubricating internal components of the system. But in addition to the lubrication of parts, the new material must also eliminate the moisture in the air, but in both systems, the fluid must be free from any dust or impurities.
3- The pressure in hydraulic systems is much more than the pressure in the new system, even at special times it reaches 1000 mega-Pascal, resulting in more hydraulic resistance.
4- At low speeds, the precision of the actuator is very undesirable if the accuracy of the hydraulic actuators is satisfactory at any speed.
5- In neumatic systems with fluid air, there is no need for recirculating tubes and air storage tank
6- neumatic systems have lower efficiency than hydraulic systems.
Information about the types of hoses
In order to study on hoses, better to know more about them.
Types of hoses: PU pneumatic hoses, Nylon pneumatic hoses, Silicone pneumatic hoses, Transparent pneumatic pneumatic valves, Rubber pneumatic hoses, Rubber pneumatic hoses, Transparent pneumatic hoses,
High pressure brake hose, Steam hose, PTFE hose, Flexible stainless steel hose,
Teflon hose of a single layer of thread, Teflon hose of a twin thread, Teflon hose, Double-threaded threaded Teflon, Teflon hose, Twin-threaded hose, Teflon hose, Single layer wire, Teflon hose, Double-walled wire hose, Teflon hose,
SAE 100 R1 AT high-pressure hose, SAE 100 R1 A high-pressure hose, SAE 100 R2 AT double-layer hose, SAE 100 R2 A double layer hose, 3-wire high pressure hose, 4SP 4-wire high pressure hose, 4SH four-wire high-pressure hose, four-wire high-pressure hose R 12, six-layer high-pressure hose, six-layer high-pressure hose R 13,
High pressure hose for suction, Hose for high pressure hoses, One-layer hoses for high pressure hoses, Hollow double hinges, Hollow shaft sleeves, Hoses for high pressure hoses, Hoses for high pressure hoses.
Seamless hose for a single layer of SAE 100 R7, special pressure hose for valves, specially designed for petrol hoses, hoses for petrol, high pressure lubricating hoses, sandblasting hoses, transparent pressure hoses, pressure hoses, Oil pressure hose for foodstuffs, Oil hoses for petroleum products,
Steam hydraulic hose, Hydraulic hose, Teflon PTFE, Steam, Steam hydraulic stainless steel hose,
Hydraulic hose for pressure test, Hydraulic hose Teflon one thread layer, Hydraulic hose Teflon dual thread 600 times, Hydraulic hose Teflon one layer of wire, Teflon hydraulic hose, Twin wire, Teflon hose, Dual wire, Hose, Teflon, Twin wire, Hydraulic hose Teflon double-layer yarn, Twin-threaded teflon hose hydraulic hose,
Hydraulic hose, one layer of SAE 100 R1 AT wire, Hydraulic hose, one layer of SAE 100 R1 A wire, SAE 100 R2 AT double layer hose, SAE 100 R2 A double layer wire hose, Three-layer hydraulic hose, Three-layer hydraulic hose, 4SP 4-wire hose, Hydraulic hose, four-wire 4SH, four-wire hydraulic hose R 12, six-layer hydraulic hose, six-layer hydraulic wire hose R 13
Hydraulic hose, Vacuum suction blower, Hydraulic hose, Single hose spray, Hydraulic hose, Hollow double shaft, Hollow hydraulic hose, Hydraulic hose, Oil hoses, Oil hoses, Oil hoses, Oil hoses
Hydraulic Hose SAE 100 R5,
Hydraulic hose for a single layer of SAE 100 R7, special hydraulic hose for valves, special hydraulic hoses for petrol, hydraulic hoses for petrol, hydraulic hoses, special lubricating oils, hydraulic hose for sandblast, hydraulic hose, transparent hose, hydraulic hose, Special hydraulic gear hose for food products, Special hydraulic oil hoses for petroleum products,
Hydraulic hose for brakes
Hoses are usually used in two groups of high pressure and low pressure. The low hose pressure is fitted as a transparent hose hinge between the tank and the pump in the suction line, in addition to the oil transfer, the pump is free to slip. If the tube is used in this position, the vibration should be used in the pipe path.
You can also use the bottom of the plastic hose pressure.
Hydraulic hoses
High pressure hoses, which are much more flexible than tubes, are used between fixed and moving parts. These components are most often used in cases where rigid tubes and tubes cannot be used. An important feature of the hoses is the mitigation of system vibration and noise.
Hoses are usually made up of several layers. The first layer is rubber tubing made of synthetic rubber, Teflon or polyester. The middle layer, which has the task of bearing pressure, is usually made of wired wire mesh made of steel strands. Due to the pressure to be tolerated by the hose, this section may be composed of several different layers. The third layer, the highest layer, is made of abrasion-resistant rubber, such as polyester. This layer of hose may also be made to protect against mechanical damage in layers, from a layer to six layers.
Maximum permissible working pressure: Typically, this pressure is determined by the manufacturer, taking into account the static and dynamic pressures. The static pressure is determined by a confidence coefficient of 1: 4, that is, the maximum working pressure of the 1.4 hose explosion pressure is allowed.
Explosion Pressure: This pressure is usually determined by applying a specific test. The hose will not leak at the values below this pressure and will not explode.
Test Pressure: The hose is pressurized twice or equal to the working pressure for 30 or 60 seconds.
Length increase: In all hoses, increasing pressure is observed in all hoses. The amount of this length change depends on the layout of the woven interior.
Bending radius: In order to maintain the safety of the hose, it should not be allowed to bend in a steady state to a certain extent.
Working temperature: The high operating temperature significantly reduces the life of the hose.
The hinge connections are connected to the next connections or system ports in both internal and external threads.
Industrial hoses and hoses used in industry, industrial hoses Industrial hoses usually have cylindrical and circular cross-sections, which vary according to the type of application in industrial devices, the parameters Different types of hoses are designed and manufactured, including pressure applied to hoses, hose sizes, and chemical hose adaptability.
Industrial hoses have different types, each based on different types of use: hydraulic hoses, pneumatic hoses, hoses, hoses, hoses, hoses, silicone hoses, hoses, hoses, hoses, industrial hoses for the transfer of fluids such as oil, water, Air and so on are used at high pressures, the type used in making industrial hoses varies according to the type of customer’s use and order, but the main material used in industrial polyethylene hoses.
Industrial hoses according to the type of industry used are different types of chemicals, some for the passage of chemicals, others for the passage of oil, others are able to pass oil products, each of these hoses have different pressures and different products, such as steel , Aluminum, bronze and so on.
Hydraulic hose
Hydraulic hose is a high-pressure hose produced from synthetic plastics, heat-resisting plastics or Teflon, and is responsible for the transport of fluids for the transfer of power to hydraulic machines.
Specifications
The use of hydraulic machines in the early 1940s when engineers built. Hydraulic systems can be much lighter (lighter) and automatically lubricate. World War II was also a factor in the development of hydraulic machinery in military applications. With the advancement in the production of flexible hydraulic hoses, the way to expand the range of new and powerful machines based on hydraulic technology is to return.
Structure: Hydraulic hoses are made of three main parts, an internal tube that passes through the liquid. This pipe is reinforced with cuff links (with plastic cover), spiral wires or yarn-based textiles, and the outer protective layer has the role of protecting against air, wear, or oil or chemicals. Hydraulic hoses are designed or ordered for use in special mechanical, industrial applications. In most cases, hydraulic hoses have special fittings with special fittings and specially designed connectors for work on specific machines.
Lifespan: Hydraulic hoses are not permanent. Several factors can affect their lifespan. Highly bending the hose, twisting, knocking, pulling, squeezing or scratching the hose can reduce the length of the hose. Very low or high temperatures during operation can cause cracking and damage to the hose. The use of size and type with inappropriate weight can also damage them. The hoses need to be replaced before they break down, which requires special attention in heavy duty hydraulic machines, brakes and hydraulic machines. Hoses may be fogged, cracked, blistered, or swollen when used, or maybe they will not show a fault at the time. Hoses should be replaced on a regular basis according to manufacturers’ recommendations, so that no hoses can be prevented.
Concept (goal)
Hydraulic systems have the ability to easily multiply or force torque. The mechanical systems have a sophisticated system (gear, chains, pulleys and levers) to move the car away from the engine. However, hydraulic systems can easily transfer power from a power generator by a series of hydraulic hoses to another place to be transmitted. Fluids efficiently transmit power because they are not compressed. The force that comes into the head of a hydraulic hose is shifted slightly to the other end. Changing the size of the hose along the track can increase or decrease the transmission force on the other side.
Advantages: Hydraulic hoses can convert power from several pressure sensors to a multi-tier output. With hydraulic hoses, hydraulic machines can create extremely fast torque at a very low speed and adjust the speed and movement of the machine with a high precision. A hydraulic pump or compressor alone can provide the necessary power for many different machines and their performance with different levels of power at one time, through hydraulic hoses. Hydraulic power machines can easily work in places where there is a flammable vapor or electrical or electronic equipment that may explode.
Hose classification: Hoses have a special rating for their own types, which can be classified according to the type of fluid that they move, the temperature returns at which they work, and the amount of compression they endure. Usually this information is printed on the hose or fittings. In some cases, the hoses are printed with a model number, with a technical data sheet for all types of models.
Caution: Hydraulic systems work to operate machines under high pressure. Hoses that do not operate at high pressures can impose a very strong impact (such as a whip) on the surrounding or the operator of the machine. Therefore, they should be checked and replaced by manufacturers on the advice of manufacturers.
Fitting and sealing the tubes
Flanged fittings (Pomp harnesses)
Flange fits are the best choice for large ports and large currents.
Flange fit
Important tips on choosing the type of fitting
In conjunction with parallel ribs, sealing is not done by the threads, but the responsibility of preventing oil leakage and leakage is on the Oingding or metal bed washers. In threaded joints, the threads are in addition to the maintenance of the Rheniz rainwater connection.
Parallel threads are used for fitting ducts as commonly used. These fittings need less torque to install than cone fittings. This eliminates the possibility of distortion and cracks in the component shell when tightening the fitting.
Cone-Thread fitting
In contrast, parallel fitting may be leaked over time by vibration.
Joints with parallel threads do not deform during installation, and they can be reused, while cone fittings are restricted for reuse.
Flange fitting is the best choice for large ports and large currents.
These joints are sealed by the orange compressed into the groove on the flat surface around the joints.
Hose fittings
Typically, two high-pressure hoses are connected to two connector assemblies. These fittings are usually attached to the hose by a spindle or spindle. The jumper binding that is carried out by pushing a sheath over the hose is not reusable. In this case, the steel sheath is compressed by molds and presses on the hose so that distortion occurs on it. This distortion prevents the connection from the hose to break. The screw type of this connection can be used again after opening the connection.
Oil guides
In hydraulic systems, oil guides are responsible for the transfer of oil to different consumers. The oil-conducting components are classified in the following three main categories:
Fittings
Hoses (high pressure and plastic)
Pipes (including hydraulic pipes and tubes)
Oil transfer is carried out on the inputs and outlets of hydraulic components by ports on the connections. In the following, pipes and hoses constitute the major part of the transmission path. At the beginning and end of pipes and hoses, different connections are used to connect each other. In the transfer process, these components are subject to a variety of mechanical, thermal and corrosion stresses. These stresses are the most important factors in determining the size and type of oil conductors. The size of the pipes, hoses and fittings must be determined in such a way that they are capable of transmitting the total discharge and not producing a large friction flow. / Hose Pressure.
Types of threads
Different types of threads are used in various industries. Some thread types such as NPT, NPTF, BSP, BSPT, SAE, METRIC and UN / UNF are more used in the hydraulic industry. Each of these types, depending on the angle and other characteristics of the thread, can play a role in sealing and deploying parts. / Hose Pressure
Connection between connections and ports
Hydraulic components, including pumps, motors, valves, cylinders, etc., have several oil inlets and outlets and control ports, which are connected by a variety of joints in the form of flanges or pipes and hoses. Choosing how to connect properly will not only reduce costs and ease of installation, but also reduce leakage.
Three common types of fittings are used to connect pipes, tubes and hoses, and connect them to ports of hydraulic components:
Connection with parallel threads
Connector with tapered threads
Flange connection
Resource Connections (NPT, BSPT and BSP)
Cone threads are not the angle of the ribs, but the slope of their position.
Straight or straight threads are easily closed and sealed by oring.
Hard tubes and PVC hoses, PVC pipes and fittings, reinforced flexible hoses, as well as various types of granules and PVC composites. Pipes and PVC fittings of sizes 20 to 500 mm for sewage, water supply, Telecommunication and power as well as single-layer and multi-layer reinforced polyvinylchloride hoses from 1/4 to 2 inches for the use of gardening and industrial PVC and PVC granules (for different uses of pipes, electric cables, telecommunication , Shoes etc.) are also PVC-like components (PVC-NBR and PVC-EVA). For irrigation and industrial purposes, hoses are made from high quality raw materials that are supplied from domestic and foreign sources.
Information on hydraulic pipes
Hydraulic is derived from the Greek word Hydro, which means the flow of fluid movements. In the last century, the purpose of hydraulic was only water, and later, the term “hydraulic” became more meaningful and the meaning and concept of the study was about the more exploitation of water and the movement of water wheels and water engineering.
The concept of hydraulic in this century is no longer water-specific but has a broader scope and includes the rules and application of other liquids, especially mineral oils, because water due to rusting properties in industries cannot be used as a transmitter energy Due to the fact that the oil does not rust, it is used today in the industry especially for energy transfer in the control system.
In short, one can say that a technician who transmits and transmits power through fluids is called “hydraulic.” Since hydraulic hydraulics is rust-proof, so in the industry, oil hydraulics are used for lubricating parts during operation as well as for energy transfer in control systems. When the industry is named “hydraulic”, the term “oil hydraulics” is meant.
Specifically, it can be said that the field of hydraulic oil use is its dynamic and static energy, and it is in control engineering for the transmission of forces and forces.
Hydraulic equipment that makes the use of hydraulic in the industry itself has a very old history. One of the earliest of these vehicles was the hydraulic pumps, which for the first time the Kitzie Bios in the middle of the third century BC before the Christ invented a piston-type pump with two cylinders.
By the beginning of the eighteenth century, there was no new device in this field, and in the beginning of this century, many types of water wheels were invented and widely used. The sixteenth century can be considered as the development of water pumps. In this century, various types of pumps appeared in different buildings, and the construction principles of these pumps, especially of the type of gears today, are still very important and important.
At the end of the sixteenth century, the principles of hydraulic press were constructed and began to be practiced after about a century of the first hydraulic press.
The nineteenth century was the time of the use of hydraulic presses, and the beginning of the twentieth century can be regarded as the beginning and time of oil hydraulic development in industrial and industrial installations.
*905 Hydrostatic gearbox emergences up to 40 bar pressure
*1910 The Origin of Pistachio Radial Machines
*1922 Generation of Rapid Radial Machines
*1924 The emergence of axial piston machines with the desired axis
In 1940, the emergence and production of various types of tools and tools for pressures of more than 350 times, some of which are currently being produced in series.
The extensive development and application of oil hydraulic was after the Second World War, and as a result of this development, many hydraulic oil components and supplies are now standardized.
The use of oil hydraulics gives the car designers new possibilities that can simplify their design and design, especially standardized hydraulic oil components are a great help in solving design problems.
Today, the machine designer can, with the help of hydraulic oil, solve complex mechanical problems in a shorter time and, consequently, deliver the design with fewer reservoirs.
◄ Positive Hydraulic Oil Properties:
Production and transfer of strong forces by small hydraulic parts, which have a lower weight and have a weight ratio of 1 to 10 to electric devices.
*Simple installation of parts due to their standardization
*Simple transformation of rotational motion to linear movement of the silhouette (return and return)
*Ability to adjust and control hydraulic components
*Quickly reverse direction
*Starting the movement of the hydraulic parts, when placed under load.
*Ability to adjust non-bridges of force, pressure, torque, speed of working parts
*Extending the life of hydraulic components due to the presence of oil in these parts
*Simple maintenance of the devices and the hydraulic installation by the manometer
Ability to automate movements
◄ Negative Hydraulic Oil Properties:
*In contrast to these positive properties, there are, of course, negative properties in the hydraulic system, which designers should also be familiar with. It should be noted, however, that the greatest negative hydraulic property is the drop in pressure, which occurs during the transmission of compressed fluid.
*The risk is when working with strong pressures, therefore, more attention should be paid to the firmness of the nuts of the shafts with the pipes and the craters of the feeding and the path of work of the working parts.
*The lower efficiency of the hydraulic power generators compared to the mechanical force generators, due to oil leakage and the pressure drop due to the friction of liquids in the pipe and parts
*Tool car
*Pressing
*Heavy Industry Facilities
*Road vehicles and mines
*Aircraft making
*Shipbuilding
Conversion of energy to hydraulic installations
Mechanical energy is often produced by combustion engines or electro motors, which is converted into hydraulic power in hydraulic pumps, and this energy is transmitted through hydraulic tools to hydraulic parts, and mechanical energy can be retrieved from these working parts.
The development of hydraulic science began when the French scientist Pascal discovered pressure laws (1561 milliseconds) and established hydraulic as a new science. From that date onward, a period of hydraulic flood emerged and this science has entered the market dramatically. Nowadays, hydraulic in the building of industrial machinery, agriculture, road construction, aircraft, shipbuilding, automobile, utility machines, heavy industry, mining and others. . . It is used on a large scale and increases day by day. Nowadays, in many industrial processes, power transmission is considered low cost and with high precision. In this regard, the use of pressurized fluid in the transmission and control of power in all branches of the industry is expanding. The use of fluid power is divided into two major branches of hydraulic and pneumatic (which is newer). In the case of relatively low forces (about one ton) and high speeds (such as those used in belt actuators), the use of hydraulics is mainly in cases where high powers and speeds Controlled precision (such as hydraulic jacks, brakes and hydraulic steering, etc.). The question now arises as to the advantages of a hydraulic or pneumatic system compared to other mechanical or electrical systems. The following can be mentioned:
1.Simple design 2.Power increase ability 3.Flexibility and control accuracy 4.Flexibility 5.High performance 6. Reliability In hydraulic and non-hydraulic systems, there are less actuator parts than other mechanical systems, and linear movement can be at any point Or high power rotors and controls, since power transmission is carried out by high-pressure fluid flows in the transmission lines (pipes and hoses), but in other mechanical systems, components such as cam, gear, guard, lever , Etc., are used.
In these systems, it can be achieved by applying low force to high and precise force. It is also possible to control large output forces by applying a small force (such as valve closing arms, etc.). The use of flexible hoses converts hydraulic and non-hydraulic systems into flexible systems that do not mention space constraints for installing other systems. Hydraulic and non-metallic systems have high efficiency due to their low friction and low cost. Also, using safety valves and compression and heat switches, a system resistant to sudden loads, heat or excessive pressure can be made which indicates the high reliability of these systems Now that we understand the benefits of hydraulic and pneumatic systems, we will simply explain how these systems work. Hydraulic technology is the production, control and transfer of power by pressure fluid. In general, a hydraulic system performs four basic tasks.
Conversion of mechanical energy to fluid pressure under pressure from pumps
Move the fluid to the points you want by pipes and hoses
Pressure, direction and fluid flow control by hydraulic and pneumatic valves for transferring power to a pressurized (compressible or incompressible) fluid. Hydraulic pumps require mechanical force to be pressurized under pressure. It is desirable to assume that this task is carried out by pipes, hoses and fasteners. After controlling the pressure and determining the flow direction by the valves, the fluid is guided by pressure to the operators (cylinders or hydraulic motors) to provide fluid power to the required mechanical force (Linear or rotational). The basis of all Hydro systems One and the other is based on the Pascal law.1 Some definitions and terms of force: A factor that causes the movement of an object or the movement of its components, its measurement unit in the metric system, is Newton’s acronym (N) .
Pressure: The force applied to the unit area is called pressure, and in other words it can be written. The important thing in the above relation is that if the force is constant, but the surface changes, the pressure will change in proportion to that pressure. It is used to measure pressure from a Pascal unit (Pa) of 1N / m 2. For example, if we enter the fixed force N 21 on the surface of A = 5, the pressure is equal to Pa 4, and if we apply the same amount of force to B = 2, the value of the pressure will be Pa 11. Strength = Pressure is the result of resistance to the movement of the fluid. To calculate the math pressure, the force is divided over the surface. Pressure unit “load”. In hydraulic practice, it is usually kg / cm 2 once. For example, if the force in a hydraulic cylinder with a piston diameter of 21 cm is equal to 6116 kgf, the pressure generated at the back of the cylinder is calculated as:
Pressure (bar) = Force (kgf) / Area (cm2) Diameter = 10cm >> Area = 314cm2 >> Pressure = 5000/314 = 15.9 bar
To determine the pressure level in a hydraulic system, it should be noted that by increasing the pressure, smaller hydraulic elements can be used to achieve the desired tonnage.
Also, the diameter of the pipes can be chosen smaller. As a result, the cost of building a system decreases. On the other hand, with increasing pressure, oil temperature increases in the system sooner, more leaks and friction and abrasion increases. As a result, the distance between services should be shortened. Pressure noise and noise are also increased, and the desirable dynamical properties of the system are reduced. PSI is the common PSI pressure unit. A PSI is equivalent to one pound of force per square inch.
To convert PSI to bar, multiply the desired amount by 16150 (approximately 1610). For example, PSI1111 is equivalent to bar50.
To convert the bar to the PSI, multiply the pressure in 1460. For example bar111 is equivalent to PSI1401.
Pascal’s Law: The Pascal Act is the New Hydraulic Stand. This law states that the pressure applied to each point of a finite liquid is equally transmitted in all directions and equally effective on equal surfaces. In other words, the pressure that enters a liquid in a closed circuit is equal in all parts of the liquid. According to the above definition, it can be concluded: by means of pressurized fluids, the force can be transferred or converted or controlled. Therefore, since liquids are almost incompressible and cannot be squeezed by volume, and according to the above law, any pressure transmitted to them passes it. In the mid-10th century, Pascal proved his hypothesis with the construction and testing of the “Hydraulic Balance” device.
Results from the Pascal Law: 1. the pressure across the stationary fluid is constant (regardless of the weight of the fluid). 2. At any given moment, the static pressure is the same in all directions. 3. The fluid pressure is brought into contact with the surfaces vertically. As you can see in Figure 1, a Newtonian intake can provide the power of another four-cylinder. In the mid-10th century, Pascal proved his hypothesis with the construction and testing of the “Hydraulic Balance” device.
The operation of non-metallic systems is similar to that of hydraulic systems, but they use a compressible fluid such as air instead of an unpowered fluid such as oil. In non-metallic systems, to reach a high-pressure fluid, the compressed air is compressed by a compressor to reach the desired pressure and then stored in a reservoir, although the air temperature is very high after compression, which can damage the system components. The compressed air must be cooled to the transmission lines before being guided. Due to the presence of water vapor in compressed air and the condensation phenomenon in the cooling process, an optimization unit should be used to dry the high pressure air. Debit: The volume of liquid that passes through a point at a time unit is called Debit. Therefore, the longer it takes to pump a certain amount of oil, the longer it will be. Speed: The piston displacement size is called speed in a time unit. Hydraulics is divided into hydrostatic and hydrodynamic sections: Hydrostatic: The application of potential energy of pressurized fluids. Such as hydraulic presses, lifting jacks, hydrostatic hydraulic transmission systems, Hydrostatic hydrodynamic hydrostatic hydrodynamic shows a hydraulic system. Components of the following new systems: 1-Compressor 2-Pressure air dryers and coolers 3- Pressurized air storage tank 4. Control knobs.
A general comparison between hydraulic and non-hydraulic systems 1. In non-metallic systems, they use compressible fluid, such as air and hydraulic systems, from an incompressible fluid such as oil. 2. In the hydraulic systems of the oil, in addition to the transfer of power, the lubrication task of the system is also internal parts of the system, but in addition to lubrication of components, the air humidity should also be eliminated, but in both systems, the fluid should be free of any Dust and dirt type. 3. Pressure in hydraulic systems is far more than the pressure in the systems of the new ones, even in special cases, to 1111 mega-Pascal, thus the parts of the hydraulic systems should be more resistant. 4. At low speeds, the precision of the novelty drives is very unpleasant if the accuracy of the hydraulic drives is satisfactory at any rate. 5. On air systems with a pneumatic fluid, there is no need for return pipes and air storage tank. 6. Nonmedical systems have lower efficiency than hydraulic systems. The hydraulic motors or hydrostatic power transmission systems are divided into two groups of open circuit and closed circuit. In open circuit power transmission systems, the total fluid flow from the engine to the reservoir returns. In the case of a closed-circuit power transmission system, the main part of the fluid outlet from the engine is pumped back to the pump inlet, and some fluid can be removed from the closed-circuit system to create suitable conditions (such as cooling or filtering). . Oiled oil is replaced by a backup power supply circuit. Hydrodynamics: The application of fluid kinetic energy. Such as hydraulic couplings, turbochargers, …) the oil must have a speed (if the oil moves inside the pipes with minimal friction, the Laminar is slowly flowing, and if turbulent and collapsed, the Turbulence turbulent flow will arise Question: 1. What is the profile of the movement of oil inside the tubes and what factors affect it? 2. Fluid resistance to flowing is called the viscosity or viscosity of oil. How does the effect of inappropriate viscosity affect the function of the system? 3. What is the impact of the turbulent flow on the hydraulic system? Hydraulic equipment Hydraulic oil: The main ingredient required for the operation of hydraulic systems is hydraulic oil, which can be organic or artificially produced, which is then referred to as synthetic oil. The most important point about using hydraulic oil in different machines is to follow the manufacturer’s recommendations regarding the oil specifications. Otherwise, there will be no guarantee for the correct functioning without any system failures and will reduce the useful life of the floods and the o rings, followed by internal and external leaks. Maintaining the oil inside the containers in a package, away from the air and environment pollution, as well as the manner in which the oil barrels are stacked, will be of great significance to the function of the system. The choice of the type of hydraulic fluid and how it is used by specialists and designers of hydraulic equipment is determined and depends on the following parameters: Lubrication and anti-wear characteristics • Load bearing • Friction coefficient • Density • Viscosity and its changes due to temperature and pressure • Shear stability • Compatibility with sealants, other fluids, additives, water, metal particles • Heat resistance, oxidation , Fire • compressibility • air adsorption and air purification • good filterability • cheap or expensive four basic steps to select hydraulic fluid as follows: • Determine the proper fluid yield range using viscosity, density, air solubility In oil, cylinder head, fire resistance, temperature range, thermal expansion and lubrication • Check Dowl and curves containing information on the types of hydraulic fluids in order to find the best fluid required • Checking the possibility of changing the system conditions for compatibility with hydraulic fluid • Using the recommendations of fluid manufacturers of fluid viscosity is the intrinsic fluid friction or Other, fluid resistance against flow. Generally, viscosity does not indicate oil quality, but is a measure of the behavior of oil at particular temperatures and pressures. The viscosity value is fully dependent on temperature and pressure. For example, the 68 VG ISO hydraulic oil has a viscosity of between 61 and 75 at 41 ° C, while the viscosity of the oil is 111.5 ° C (5.8-5.7 cSt). By increasing the pressure of this oil from 200 to 400 bar, its viscosity doubles. High viscosity viscosity effects: • Lower pressure • Pumping more difficult • Better lubrication • Difficult air removal • Slower transmission of low viscosity • Larger lubrication • Less oiling • Less pressure drop • Easier pumping • Fast signal transfer • Extracting air more easily.
Oxide Oxidation: When moving fluid from regions under atmospheric pressure towards the points with the maximum pressure of the system, the adiabatic density of the bubbles increases the extreme temperature. High heat, which cannot be repaired, causes rapid oxidation of the oil.
Hydraulic tank or tank: Despite the simple appearance, the design and construction of a hydraulic tank must be observed: the tank capacity depends on the total oil in the pipes, cylinders, accumulators, oil coolers, filters, … 11 to 21% of the additional oil. To prevent the risk of emptying the tank or creating a foam in oil due to the separation of the oil level from the return pipes. The installation location is considered in terms of height and also in the vicinity of the hydraulic unit, ambient temperature, non-interference with access to other equipment, and the possibility of easy emptying and easy filling of the tank. Design and installation of shock absorbers for preventing hydraulic turbulence. – Install glass sight or level gauge and lumber to determine the amount of oil in the tank. – Install the air filter to ventilate the air inside the tank and prevent the vacuum. The oil tank should have the following functionalities: • the ability to store the entire system of oil • Separate the air contained in the oil • Precipitate deposits in the reservoir • the heat recovery of the oil tank system should have a sufficient volume to compensate for the expansion of the oil in the reservoir. Tanks should be made to be tall and shallow. In shallow reservoirs there is the possibility of air entering the suction port of the pump. Dimensions of the tank: Dimensions of the oil tank in the industrial system Volume of the oil tank Three to five pumps (min / lit) Dimensions of the oil reservoir in the mobile system per 100GPM of pump, volume of tank of 30- 20 gallon. Many of the filters are inadequate in the hydraulic system due to extremely dirty oils. • Suction filter • Pressure line filter • Back line filter • Filter with filter design and selection criteria • Sensitivity of components used in the hydraulic system to external particles • Flow rate determination • Permissible pressure differences • Filter material compatibility with used oil • Operating temperature • The viscosity of oil in determining the filter size is considered to be: • The amount of environmental contamination in which the system is located. • Hydraulic system maintenance and service • Operating temperature of the oil The size of the oil inlet filter to the pump is usually 3 to 4 times the pump flow rate. Inputs of contaminants and foreign particles to the hydraulic system: • External contaminants • Assembly • Start-up • Inner particles • Abrasion • Repairs
Hydraulic and pneumatic applications
Hydraulic system is used in the following cases
1- in the agricultural industry: that the farmer can drive tractors
Use the power of fluid and also in devices such as grubbing and chopping
Flaxseed and Fruit, China Drilling Machine and Mechanical excavator
2- In automobile: more hydraulics and hydraulic steering and pneumatic seat adjustment, as well as in the body construction process and forming a sheet of automobile used in different presses.
3. In the pilot’s air, with this system, the chassis of the landing gear and the vertical and upright runners hinges on the lacquer and the airbag body is made with tensile presses.
And it’s interesting to find out that the body of the aircraft is not pierced to put pressure on the walls of the body to test. If we have a drop in pressure, we will find that it is a hole in the body.
Airplane tests are:
1. The wind-driven test is 300 times pressurized
2.Test all aircraft hydraulic system
3. Testing the aircraft body
4. Mill for testing the F14 airplane
5. Defensive Defense: In guiding the tanks of the people and guiding the missile and in the wars, guiding the ship …
6. Food processing: canning and disposable containers and …
7. Wood Sticks: Cut timber and planted sofa surfaces
8. Instead of materials (lifts and cranes, etc.)
9. CNC turning machine and the like
10. Seafood: Taking a tour of the water and pulling a ship to the coast ……
11. Mine: In mining machines
12. In packaging industries: filling glasses of soda and scouring machines
13. Cooking: In this industry, paper pulp must pass through the rollers and the most important hydraulic and pneumatic roller arrangement.
14. Petroleum Industry: Poles
15. Plastic industry
16. Printing industry:
17. Rail: More new automatic cost meter
18. Rubber:
19. Steel industries: high pressure for iron or metal traction and drainage of furnaces in Mobarakeh steel and iron mills.
20. Textile
Hydraulic and pneumatic systems
The components of the pneumatic system are:
1.The compressor of the wind: which has a reservoir that stores air in the air by itself, just like a gas cylinder, but with the difference that it is inside the gas cylinder, but in the air compressor, you may have seen the air compressor in the airplanes. Which is stored using an electric motor or diesel engine or gasoline engine inside it.
2. Pneumatic Cylinder: We use cylinders for linear or rotational motion. The store has many years of supply and distribution of hydraulic equipment.
Today, in many industrial processes, the transmission of power is also low cost and with high precision. In this regard, the use of pressure fluid in the transmission and control of power in all branches of the industry is expanding. The use of fluid power is divided into two major hydraulic and pneumatic branches (which are newer):
The use of a neuromatic system in cases where relatively low forces (about one ton) and high motor velocities are needed (such as those used in belt actuators), while applications of hydraulic systems are mainly in cases where high powers and speeds precisely controlled controls (such as hydraulic jacks, brakes and hydraulic steering, etc.)
What is the benefit of a hydraulic or pneumatic system than other mechanical or electrical systems? The answer is:
1. Simple design 2. Power increase 3. Simple and precise control
4. Flexibility 5. High efficiency 6. Reliable
In hydraulic and pneumatic systems, there are fewer actuator parts than other mechanical systems, and high-power and high-speed linear or rotational movements can be achieved at any point, since power transmission by high-pressure fluid flows in transmission lines (tubes and Hoses are used, but in other mechanical systems they use components such as cam, gear, car, lever, clutch, etc…)
In these systems, it can be achieved by applying a low force to the high and precise force. Also, large output forces can be controlled by applying a small force (such as the valve closing the valves, etc.)
The use of flexible hoses turns hydraulics and pneumatics systems into flexible systems that do not mention the space constraints that are being used to install other systems. Hydraulic and pneumatic for low friction and low cost of high efficiencies are also using safety valves and switches, pressure and temperature may be resisting system loads, shock, heat or excessive pressure, which indicates the reliability of these systems has it.
In order to transfer power to a pressurized (compressible or incompressible) fluid, it is possible that mechanical pumps can be forced into fluid pressure under hydraulic pressure. The next step is to transfer the force to the desired point, which will assume the task of pipes, hoses and fasteners.
After controlling the pressure and determining the flow direction by the valves, the fluid is guided by pressure to the operators (cylinders or hydraulic motors) to convert the fluid’s power to the required mechanical force (linear or rotational).
The work of the new system is similar to that of a hydraulic system, but it uses a condensing fluid such as air rather than an incompressible fluid, such as oil. Systems pneumatic to achieve a fluid-pressure air by a compressor compresses the pressure desired is then stored in a repository, although the temperature of compressed rise greatly as can be system components injuries Therefore, compressed air should be cooled to the transmission lines before being guided. Due to the presence of water vapor in compressed air and the condensation phenomenon in the cooling process, an optimization unit should be used to dry the high pressure air.
2. Two-phase processes
Introduction
The most important characteristic of the two-phase currents is the presence of gas-liquid phases. This chapter has several forms. It is almost possible to find an infinite domain of a common interface between the two phases, but generally the effect of surface tension between the two phases leads to the emergence of different curved joint chapters, which eventually all become spherical forms (such as drops and bubbles) be.
In general, we can explain and interpret these types of streams by classifying the different modes of distribution between the two phases of gas and liquid known as flow regimes or flow patterns. It should be noted that these flow regimes are usually influenced by the position and geometric shape of the pipeline and the direction of flow and physical properties, and the intensity of each phase and the thermal flux on the wall of the tube.
It should be noted that in spite of the many efforts made to classify various two-phase flow regimes, all of these methods are highly qualitative and often in accordance with the personal point of view of the researchers, so far different regimes have been defined. And a wide range of names have been used for this purpose. The definitions that will be presented here for a variety of diet regimes are summarized in a very brief way. Before the expression, the concept of fluid flows in the pipelines is discussed.
Flow pattern in horizontal pipelines:
There are seven types of distribution patterns for two-phase flows in horizontal pipelines. These flow patterns are displayed in the form of subsequent pages. So that for each flow regime, the flow rates of each phase are calculated for a mixture of gases with a specific mass close to the specific mass of air and liquids with a viscosity less than 100 centimeters.
Bubble stream:
In horizontal pipelines in cases where the volume of gas is relatively low and the volume of liquid volume is relatively high, the bubble flow appears as a small gas bubble under the influence of the density difference in the upper part of the pipe. By increasing the volumetric volume of the gas phase, the size of the bubbles increases gradually. The apparent fluid velocity in this type of flow is between 5 to 15 ft / s and the apparent gas velocity is between 1 and 10 ft / s.
Hub or ball flow:
As the gas phase velocity increases in the bubble, the number of gas phase bubbles increases. So that large bubbles and hubs close to the upper wall of the tube will be formed from their collision. This type of stream is called a ball or hub.
Layer flow:
In this type of distribution pattern, the liquid and gas phases are completely separated, and the gas phase, which generally has a faster rate than the liquid phase, moves in the upper and lower parts of the bottom in the tube. Interference between two phases is rarely done, and the interface between them is fairly regular and smooth. In this case, the apparent speed of the liquid phase is less than 0.5 feet per second, and the apparent speed of the gas phase is between 2 and 10 feet per second.
Waveguide:
In the course of the layer, if the gas velocity increases, it will increase again. There is a tension between the gas phase and the liquid that causes the waves to occur in the joint, which moves along the flow. The apparent speed of the liquid in this case is less than 1 ft / s and the apparent gas velocity is about 15 ft / s.
Cold Flow: slug flow
In the horizontal pipelines and in cases where the flow rate is high, the gas velocity increases the range of liquid surface waves in the gas-liquid interface, whereby the waves collide with the upper wall of the tube and forms liquid liquids. Liquid clusters in such a situation can cause severe vibration and, in some cases, a hazard inside the equipment located along the pipelines and centers. One of the characteristics of this type of flow regime is the regular fluctuations in pressure variations and accumulated fluid content, which is a good measure for detecting this type of flow regime.
Circular Flow:
In this type of flow, the two phases of gas and liquid will flow through the two cylinders interposed inside the tube. This type of flow will be formed when the apparent gas velocity is greater than 20 ft / s. A precise study of this type of flow pattern to determine the amount of abrasive corrosion and increase the flow efficiency of the prediction of the accumulated fluid amount and determine the thickness of the liquid film on the pipe wall and calculate the pressure loss of the fluid to design the pipelines and its end equipment is of particular importance. .
Droplet flow:
By increasing the flow rate of the gas phase in the cylindrical flow of the gas phase and the liquid phase will be transmitted as a droplet. It is likely that such a flow will occur when the apparent speed of the gas phase is more than 20 ft / s. In cases where the gas flow rate is relatively high and the flow rate is relatively low. The liquid phase in the gas phase becomes a very small and dispersed particle, and thus a space like a fog. In this case, the current flow is called foggy. Some of the condensate gas transfer pipelines are in this particular pattern at certain times.
Flow patterns in vertical pipelines
There are patterns in the vertical pipelines that do not differ much from the patterns of flow in the horizontal pipelines.
Bubble stream:
In this type of fluid, the flow of liquid phase moves continuously and the gas phase disperses (fine bubbles) into the liquid upward. The phase velocities in this type of flow are different due to the difference in the specific mass of the phases. Generally, small gas bubbles pass through the liquid phase at an apparent speed of less than 2 ft / s.
Cold stream:
In the bubble stream, with increasing gas velocity, the number of bubbles increases, and when they collide with each other, several gas droplet domes arise that occupy the entire pipe section in parts of the tube. In practice, this type of flow is continuously interrupted by liquid and gas phases, with a high pressure drop, and also in terms of process, causing annoying noise and damage to the equipment. In the design of two-phase flow pipelines, we try to avoid the possibility of such a flow regime being avoided. In this case the apparent velocity of the gas phase varies from 2 to 30 feet per second.
Foul flow:
In the clot stream, the flow rate of the masses of the gas will be broken down and the unstable and transient flow between the two flowing and circular flows will be formed. In flowing pipelines with large diameters, swirling fluid moves up and down, while in the narrow tubes this oscillatory movement will not occur, and the transition between two types of flocculent and circular flow will be very transient.
Droplet flow:
In this type, the flow of gas phase is continuous and the liquid phase moves along with it in fine particles. The gas phase transmits the liquid phase in fine droplets. In this case, changes in the pressure of the fluid are controlled by the gas phase. Experimental data show that for the apparent gas phase of more than 70 ft / s and the apparent speed of the liquid phase is less than 2 ft / s, this kind of regimen will turn into circular current.
Hydraulic Pumps
Due to the increasing influence of hydraulic systems in different industries, pumps with different power and pressure are needed more than ever. The pump, as the heart of the hydraulic system, converts the mechanical energy that is supplied by electric motors, internal combustion, etc. to hydraulic energy. In fact, the pump in a hydraulic or non-mechanical cycle increases the fluid’s energy to be converted to the desired location in the required location of this energy.
The atmospheric pressure caused by the relative vacuum caused by the operation of the mechanical components of the pump forced the fluid to move into its inlet to be driven by pumps to other parts of the hydraulic circuit.
The pressure of the high pressure oil delivered to the hydraulic circuit depends on the pump capacity and, consequently, on the volume of displaced fluid per round and the number of rounds of the pump. The pump capacity is expressed in gallon units in minutes or liters per minute.
Noteworthy in fluid suction, the permissible vertical height of the pump is relative to the free surface of the fluid; in the case of oil, this height should not be more than 10 meters, since the result of the creation of a relative vacuum if the height is greater than 10 meters, oil is boiled and instead of liquid oil Oil vapor enters the pump and will cause a malfunction during the cycle. But there is no limit to the pump outlet height, and only the power of the pump can be determined.
The pumps in the hydraulic industry are divided into two general categories:
1-Non-positive displacement pumps (dynamic pumps)
2-Pumps with positive displacement
Non-positive displacement pumps are not able to withstand high pressures and are rarely used in the hydraulic industry and are usually used as primary fluid transfers from point to point. Generally, these pumps are suitable for low pressure and high current systems with a maximum compressive capacity of 250 psig to 3000 si. Centrifugal pumps (Centrifuges) and Axial Applications are non-positive displacement pumps.
Positive displacement pumps: In these pumps, for each turning axis, a certain amount of fluid is sent to the outlet and capable of overcoming outlet and frictional pressures. These pumps have many advantages over non-positive displacement pumps, such as smaller dimensions, high volumetric voltages, good flexibility and ability to operate at high pressures (even greater than psi)
Pumps with positive displacement in terms of building:
1. Gear pumps
2. Impeller pumps
3. Piston pumps
Pumps with positive displacement in terms of displacement:
1-Pumps with fixed displacement
2-Pumps with variable displacement
In a fixed displacement pump, the amount of fluid pumped per axial rotation is constant, whereas in pumps with variable displacement, the above value is due to a change in the relationship between low or high pump components It is. These pumps also have variable discharge pumps.
It should be kept in mind that the pumps do not cause pressure, but they produce flow. In fact, in a hydraulic system, the pressure indicates the resistance to the pump output. If the output is at the pressure of an atmosphere, then no pump outlet pressure will exceed one atmosphere. Also, if the output is at a pressure of 100 atm, a fluid pressure of 100 atm can flow into the fluid.
Gear Pump Gear Pumps
These pumps have been used extensively for cost-effective construction, low cost and compact construction. But the disadvantages of these pumps can be reduced their efficiency due to erosion of parts due to friction and corrosion, and as a result of leakage of oil in its internal parts. This pressure drop is noticeable in the areas between the ribs and the crust and between the ribs.
Gear pumps:
External Gear Pumps
Internal Gear Pumps
3. Lobe Pumps Earrings
Screw Pumps
5. Gerotor Pumps
In these pumps, one of the gears is connected to the actuator and the other gear is free of charge. By rotating the actuator axis and disengaging the gears from the gears, the relative vacuum of the oil is drawn into the space between the gears and the crust and driven to the outlet.
The gap between the shell and the gears in these pumps is approximately (0.025 mm).
The internal loss of flow is due to the oil summation in the space between the shell and the gear, called volumetric efficiency.
Due to the high pumping speeds up to 2700 rpm, the pumping is very fast; this value varies from 750 rpm to 1750 rpm in gear pumps with variable displacement. Gear pumps are designed for pressures up to (kilograms per square centimeter 200) of 3000 psi, which is of course a standard size of 1,000 psi.
Internal Gear Pumps
These pumps are mostly used for lubrication and feeding at pressures of less than 1000 psi but in multi-stage types, access to a compression range of about 4000 psi is also possible. The reduction in abrasion performance on internal gear pumps is higher than external gear pumps.
3-Lobe Pumps
These pumps come from the family of gear pumps that are quieter and more inert than other pumps in this family, since both gears have external actuators and the gears do not interact with each other. But it has more pulse outputs due to its lower teeth, but it has a larger displacement than other gear pumps.
4- Screw Pumps
The screwdriver pump is a gear pump with positive displacement and axial flow that is caused by the clash of the three screws in the sealed enclosure, producing a very slow, high-pulse and high-current flow. Two rotary rotors act as rotary feed water and cause fluid to move in the right direction. Slow motion without sound and vibration, feasible with a variety of fluids, minimum lubrication, water and oil emulsion pumping, and no disturbance. At the output of this pump are the interesting advantages.
5- Gyrator Pumps
The function of these pumps is similar to the internal gear pumps. In these pumps, the gyrator member moves by the external actuator and causes the rotor to rotate the gears involved with it.
As a result of this conflict mechanism, sealing is provided between the pumping areas. The gyrator member has a smaller tooth gear than the internal gear rotor.
Dent volume reduced multiplied by the number of gear wheels of the actuator, the volume of pumped fluid per turning axis.
In general, blade pumps are used as medium pressure pumps in the industry. Their speeds usually range from 1200 rpm to 1750 rpm, and at specific times up to 2400 rpm. The volumetric performance of these pumps is 85% to 90%, but their overall efficiency is low due to leaks around the rotor (about 75% to 80%). Most of these pumps work slowly and quietly, and the advantages of these pumps are that it can be repaired in the event of problems in the pump building without separating the inlet and outlet pipes.
The space between the rotor and the cam rim in the first half of the first rotation of the axis is increased and the volume expansion causes the pressure to decrease and the suction is carried out, as the fluid flows to the inlet of the pump. In the second half, with the space gap between the blades, the fluid in these spaces is pushed by pressure to the outlet. As you can see in Figure, the flow generated by the center of the center (the distance between two centers) axis depends on the pump rotor, and if this distance reaches zero, we will no longer have the flow output.
These pumps, which have the ability to set the exit from the center, can pump different volumetric volumes into the system. These pumps are called variable displacements. Because of the center-axle exit of the rotor (asymmetry), the lateral load on the bearings increases and creates a problem at high pressures.
To solve this problem, symmetric blower pumps (balances) are used. The elliptical shape of the shell in these pumps makes the inlet and outlet ducts face upwards and create a hydraulic equilibrium. With this trick, the lateral load on the bearings is reduced, but the inability to change in displacement is considered to be the disadvantages of these pumps (since there will be no exit from the center)
The maximum available pressure on the blade pumps is about 3000 psi.
Piston pumps
Piston pumps with the highest ratio of power to weight are the most expensive pumps, and in the case of accurate sealing, the pistons can have the highest efficiency. Usually, the flow in these pumps is without a pulse and due to the failure of the lateral load to the pistons have a long life, but due to the complex structure of repair it is difficult.
In terms of design, the piston pumps are divided into two radial and axial groups.
Axial Piston Pumps (bent-axis type):
In these pumps, the center line of the cylinder block is located at a certain angular position relative to the center line of the drive axle. The piston rod is connected to the drive shaft flange by the ball and socket joints so that the spacing between the drive flange and the cylinder block Swaying the pistons in the cylinder. A universal link connects the cylinder block to the drive axis.
The output of the pump can be changed by changing the angle between the two pump axes. There is no output at zero angle and the maximum output is obtained at a 30 degree angle.
Axial piston pumps (Swash plate) axial piston pumps:
In this type of pump, the axle of the cylinder block and drive axis are in the same direction and during the rotational movement, due to the position of the plate, the pistons will perform a reciprocating movement, with this movement, the fluid will flow from the inlet and in the outlet They pump. These pumps can also be designed with variable displacement properties. In variable displacement pumps, the position of the angle plate is adjusted by manual, servo or compensating system. The maximum angle of the angle plate is about 17.5 degrees.
Radial piston pumps
In these types of pumps, the pistons are positioned along the radius. As a result of the centrifugal force and the pressure of the fluid behind them, the pistons always react with the surface of the rim.
In order to pump the fluid, the reaction must be in relation to the drive axis of the outlet center. In the area where the pistons are located away from the axis of the rotor, the relative vacuum produced by the suction is carried out. In the course of the rotor’s time, the pistons approach the axis and The fluid in the rotor is pumped to the outlet. Variable displacement of these pumps can change the output of the system by changing the exit from the center of the rim. The response to the drive axis can be changed.
Plunger pumps
Planter pumps or high-capacity reciprocating piston pumps are used in industrial hydraulics. The capacity of some of these pumps is about a few hundred gallons per minute.
The pistons in the upper space of a cam shaft (including a number of outboard center roller bearings) are positioned linearly. Fluid entering and leaving the cylinders is carried out through valves (one-valve valves).
Pump performance:
The efficiency of a pump generally depends on the degree of tolerance and precision used in the construction, the mechanical condition of the components and the pressure balance. In the case of pumps, three types of efficiency are calculated:
1-The volume yield that determines the leakage rate in the pump and is obtained from the following equation
(The theory of the pump to be pumped / the actual pump flow rate) = volume yield
2-Mechanical efficiency that determines the amount of energy lost due to factors such as friction in the bearings and components involved, as well as turbulence in the fluid.
3-Mechanical efficiency
4-(Actual power given to the pump / power theory required for the pump operation)
5-The total efficiency that determines the total energy dissipation in a pump and is equal to the efficiency of the mechanical yield in the volume yield.
6- Hydraulic design of pipelines
Transmission of two-phase currents in steady state
Introduction
Typically, the hydraulic design of the two-phase duct transfer pipelines in a steady state is carried out using one of the following methods:
Using appropriate single-phase flow equations along with a safety factor
Use of equations and equations for stable two-phase currents
In the first method, empirical relationships or appropriate analytical equations in the design of single-phase flow transmission pipelines along with a safety factor are used because of the high pressure drop in the two-phase flows for the design of two-phase pipelines. It should be noted that the results of this method generally lead to two over design and design less. Doing too much design does not have major problems if the design is less than the size of the pipe and its accessories. Also, when the amount of condensed liquid inside the pipeline is negligible, using this method can be very effective in preventing a design that is less than pipeline size. In most cases, the amount of condensed liquid inside the pipeline is sufficiently significant, and the use of this method will lead to large errors in the calculation.
However, in the second method, empirical relationships are used to calculate the design of two phase gas pipelines. As all these empirical relationships are based on limited information specific to pipelines with low diameter at low pressures and for simpler systems such as water mixtures. The conditions applied to the accuracy and flexibility of the above method creates a limitation in the application of this method as a design tool for the design of two-phase pipelines. So that the extrapolation of this information and the use of these experimental relationships in the design of operational and actual pipelines of two-phase flows will result in many errors in design.
It should be noted that the existing experimental relationships for the design of two-phase flow currents can be categorized into three categories as follows:
In the first category, the slip between the two gas and liquid phases and the flow regime changes are not considered. Therefore, the specific mass of a two-phase mixture is calculated based on the ratio of the accumulated fluid in non-slip mode in each part of the pipelines, and only one relation is needed for the frictional coefficient of the two-phase flow.
In the second category, the slip between the two phases is considered between the two, but the flow changes are not considered. In this method, two separate equations are used to calculate the coefficient of friction and the amount of accumulated fluid.
In the third category, the slip between the phase and the flow changes are considered. In this group, in addition to using different relationships to calculate the accumulated amount and the coefficient of friction equations, also to predict the type of two-phase flow regime. It determines the type of flow regime of the corresponding equations.
It is noteworthy that the mechanism of flow regime changes is not physically taken into account in some cases and is used to determine the flow regime from the experimental curves.
Obviously, the results of the third category are more precise than the other two, and empirical relations between the two other categories can be used when the assumptions considered in them are acceptable to apply the conditions. For example, when the gas flow rate is high and the biphasic two-phase flow regime is fatal, the slip between the phases can be saved.
The design steps of the two-phase flow lines for determination of the pressure loss and accumulated fluids are as follows:
Step 1: Determine the composition of the percentage of volumetric flow rate and operating conditions of the gas entering the pipeline.
Step 2: Determine pipeline specifications such as length diameter and pipeline height changes
Step 3: Determine the total heat transfer coefficient and perform thermal equilibrium in a section with a specified length of the pipeline
Step 4: Performing a sudden evapotranspiration and thus determining the enthalpy of each of the gas and liquid phases using a suitable state jumper in a piece with a specified length of the pipeline
Step Five: Determine the types of flow patterns available within each part of the pipeline.
Step 6: Calculate the pressure loss and accumulated fluid in each section of the pipeline according to the type of flow regime in that part, and then determine the total values of the pressure drop and the accumulated fluids along the entire pipeline. At this stage, it should be noted that if the flow within the two-phase pipeline is stable, then empirical relationships or appropriate analytical equations should be used.
Also, in the case of unshielded two-phase duct pipelines design, appropriate analytical equations should be used to determine the types of unstable two-phase flow regimes, as well as to calculate the pressure loss and accumulated fluid concentrations within the pipelines.
Effective factors in hydraulic design of two-phase currents
To make accurate calculations of the preliminary design of two-phase flow transmission pipelines, the following points should be considered:
1-When designing pipelines, stable two-phase flows using empirical relationships. Of course, it should be noted that any existing empirical relationship based on the database of the tested system has expanded rightly and it is not possible to explicitly prefer one relationship to another. So that some of these empirical relationships provide an acceptable answer within a range and outside of that limit the range of unacceptable answers. Considering the above points, it is more appropriate to design these pipelines. Using the existing methods, select a low and high range for the design parameters and make the design in such a way that the results are within the range. It is worth noting that in this case, the design must be done in such a way that the pipeline has the ability to withstand the potential oscillations of the pressure from a minimum to a maximum. As well as the necessary measures for the end equipment of the pipeline.
2-Proper design of a two-phase flow transmission pipeline if it is compatible with the actual conditions to be used as the basis for the existing two-phase duct pipelines, then the existing pipeline must first be free of accumulated liquids and then, according to the design conditions, in Different volume volumes measure the values of pressure drop and fluid accumulated inside the pipeline. According to the information obtained, the two-phase flow transmission pipeline can be designed with higher precision and higher efficiency.
3-In designing a two-phase flow transmission pipeline it is necessary to consider the characteristics that represent the actual image of the use of that pipeline in the future. Such an image can be evaluated by considering the following conditions:
Rheological conditions
Reservoir conditions
Production conditions
Consumer need
For example, since the performance and behavior of hydrocarbon reservoirs is such that the ratio of gas to liquid is proportional to time, the exact amount of volumetric flow rate of the two-phase flow within the pipeline is not specified and therefore the design of the two-phase flow pipeline is based on the guesswork and error method And is performed at a volumetric rate lower than the designed capacity.
Information on hydraulic fitting
Types of threads
Different types of threads are used in various industries. Some threads types such as NPT, NPT, BSP, BSPT, SAE, METRIC and UN / UNF are more widely used in the hydraulic industry. Each of these types, depending on the angle and other characteristics of the thread, can play a role in sealing and deploying parts. / Hose Press Machine/ They have a significant role in sealing and deploying parts.
Relation between fittings and ports
Hydraulic components include pumps, motors, valves, cylinders, etc. There are several oil inlets and outlets and control ports, which are connected by a variety of joints in the form of flanges or joints with pipes and hoses. Choosing how to connect properly will not only reduce costs and ease of installation, but also reduce leakage.
Three common types of fittings are used to connect pipes, tubes and hoses, and connect them to ports of hydraulic components:
Connection with parallel threads
Connector with tapered threads
Flange connection
Threaded Joints (NPT BSP and BSP)
Cone threads are not the angle of the ribs, but the slope of their position.
Straight threads are easily closed and sealed by O-ring.
Connecting and sealing the tubes
Flanged fittings (Pomp harnesses)
Flange connections are the best choice for large ports and large currents.
Flange connection
Important tips about choosing the type of fitting
In conjunction with parallel ribs, sealing is not done by the threads, but the responsibility of preventing oil leakage and leakage is on the Orin ding or metal bed washers. In threaded joints, the threads are in addition to the maintenance of the Rienzi rainwater connection.
Parallel threads are used for connecting ducts as commonly used. These fittings need less torque to install than cone fittings. This eliminates the possibility of distortion and cracks in the component shell when tightening the connection.
Connections with tapered threads in reverse, parallel connections may be leaked over time due to vibration.
Joints with parallel threading do not deform during installation, and their reuse is possible while conical joints are restricted for reuse.
Flange connection is the best choice for large ports and large currents. These joints are sealed by the orange compressed in the groove on the flat surface around the joints.
Hose fittings
Typically, two high-pressure hoses are connected to two connector sets. These fittings are usually attached to the hose either by spindle or spinning. The press fit that is carried out by pushing a sheath over the hose cannot be reused. In this case, the steel sheath is compressed by special molds and presses on the hose so that distortion occurs on it. This distortion prevents the connection from the hose to break. The screw type of this connection can be used again after opening the connection.
Oil guides
In hydraulic systems, oil guides are responsible for the transfer of oil to different consumers. The oil-conducting components are classified in the following three main categories:
Fittings
Hoses (high pressure and plastic)
Pipes (including hydraulic pipes and tubes)
Oil transfer is carried out on the inputs and outlets of hydraulic components by ports on the connections. In the following, pipes and hoses constitute the major part of the transmission path. At the beginning and end of pipes and hoses, different connections are used to connect each other. In the transfer process, these components are subjected to various mechanical, thermal and corrosion stresses. These tensions are the most important factors in determining the size and type of oil conductors. The size of the pipes, hoses and fittings must be determined in such a way that they are capable of transmitting the total discharge and not producing a large friction flow. / Hose Pressure
By reading this article in the field of hydraulic joints, hydraulic hose, you will get an insight into how they are used in industry and what products made from our mines are made for the industry.
1-Advances in the field of hydraulic hose assemblies
2-Use of hydraulic hoses – Mineral products
Advancements in the field of assembly of hoses and hydraulic fittings
Hydraulic hoses are used in a wide range of market segments throughout the world as a means for conveying gas or high pressure liquids in machinery and industrial plant processes. The potential leakage risks of high pressure fluid transfer are very high, so they test the required safety mechanisms through precise testing methods. All auxiliary adapters, main components of hydraulic connections (hydraulic couplings), valves and other hydraulic connections Hoses are fully tested under real conditions to control stability and flexibility.
Main adapters
Today, there are hose clamps in the market, most notably the main hydraulic hose adapter. The main adapters are an effective and important mechanism for connecting two hose heads, which are used for high pressure liquid transfer in hazardous environments, including underground mines and tunnel construction. The correct connection requires the intense pressure of the two ends of the hose, and in order to do so, the main adapters are used as a lock, which in fact is a curved piece of steel, forming a U-bend, which is located on both sides of the hermetic sealing hinges Placed.
The main turning bundle
Large-scale mine drill mining requires hydraulic hoses that can move freely during high-pressure liquid transfer when the vibrations from the environment come with heavy impact to the hose. The main rotary hinges for such applications were designed and developed to reduce the torsion stress by allowing free movement of the hose parts during operation, while maintaining the high-pressure lock mechanism.
Protection of hydraulic hose parts
Despite the hazardous environments that parts of the hydraulic hoses need to work on, there is a need for protective solutions that can protect the exterior surfaces of the hoses used in place. Designed and tested today to protect layers to protect against wear and temperature. It can be used for single or dual hoses used in mining and other industrial environments. These hose reels are ideal for oil extraction and electrical cabling. And there are even a variety of silicone protective coatings for fire resistance.
Hose fittings
Hose fittings, which are custom-made for many applications around the world, are custom-made for use in specific locations in different parts of the market, in common with the environment in which hydraulic hoses are used. Although some of the more generic products can be purchased online, but a wide range of them should be ordered to manufacturers who are able to produce custom fittings for hoses according to international industrial precision standards. Completely tested.
2-Applications of hydraulic hoses – mineral products
Mining hydraulic hose products are used in some industries, including coal mining, tunnel construction, and oil and welding processes. They allow liquids to be transported at high pressure in hazardous environments safely and safely. The hoses are made of high quality rubber and highly insulated to increase their durability and enable fluid to flow at the same speed, which is essential for the industry in which they are used.
High pressure hoses and hydraulic fittings in mining
Hydraulic hoses and hydraulic fittings are ideal for mining, especially those mines where dehydration is needed. The water used to continuously cool down the mining machines over long periods of time overnight should be transferred from the surface to the surface of the coal, or pumped and re-exhausted. The use of high pressure hydraulic hoses is transferred to the outside of the mine to be re-pumped. Obviously, water must be returned to the same extent as freshly-cooled water is pumped in to maintain a balance, otherwise the mine will quickly flood (flood).
Hydraulic fittings mining hoses
Hydraulic joints and hydraulic hoses used in the precisely suitable range for this work are made by adding a thermal insulation coating to minimize the damage caused by the passage of water or other fluids to high pressure and heat over time. Water extracted from the mine is not clean water because it is full of dirt and debris remaining from mining machines and can damage the inner layer of the hydraulic hose. Because of this, specially designed hoses and hydraulic fittings are designed to withstand such damage as well as high water pressure. All hydraulic connections, including adapters, hoses, hub valves and couplings (couplings) are all tested in high pressure high pressure controlled environments to ensure that they all have adequate resistance to use in years there are many in the industry.
Hydraulic hose
Hydraulic hose is a high-pressure hose produced from synthetic plastics, heat-resisting plastics or Teflon, and is responsible for the transport of fluids for the transfer of power to hydraulic machines.
Specifications
The usage of hydraulic machines in the early 1940s when engineers built. Hydraulic systems can be much lighter (lighter) and automatically lubricate. World War II was also a factor in the development of hydraulic machinery in military applications. With the advancement in the production of flexible hydraulic hoses, the way to expand the range of new and powerful machines based on hydraulic technology is to return.
Structure: Hydraulic hoses are made of three main parts, an internal tube that passes through the liquid. This pipe is reinforced with cuff links (with plastic cover), spiral wires or yarn-based textiles, and the outer protective layer has the role of protecting against air, wear, or oil or chemicals. Hydraulic hoses are designed or ordered for use in special mechanical, industrial applications. In most cases, hydraulic hoses have special fittings with special fittings and specially designed connectors for work on specific machines.
Lifespan: Hydraulic hoses are not permanent. Several factors can affect their lifespan. Highly bending the hose, twisting, knocking, pulling, squeezing or scratching the hose can reduce the length of the hose. Very low or high temperatures during operation can cause cracking and damage to the hose. The use of size and type with inappropriate weight can also damage them. The hoses need to be replaced before they break down, which requires special attention in heavy duty hydraulic machines, brakes and hydraulic machines. Hoses may be leaking, cracked, blistered or swollen when used, or maybe they will not show a fault at the time. Hoses should be replaced on a regular basis according to manufacturers’ recommendations, so that no hoses can be prevented.
Concept (goal)
Hydraulic systems have the ability to easily multiply or force torque. The mechanical systems have a sophisticated system (gear, chains, pulleys and levers) to move the car away from the engine. However, hydraulic systems can easily transfer power from a power generator by a series of hydraulic hoses to another place to be transmitted. Fluids efficiently transmit power because they are not compressed. The force that comes into the head of a hydraulic hose is shifted slightly to the other end. Changing the size of the hose along the track can increase or decrease the transmission force on the other side.
Advantages: Hydraulic hoses can convert power from several pressure sensors to a multi-tier output. With hydraulic hoses, hydraulic machines can create extremely fast torque at a very low speed and adjust the speed and movement of the machine with a high precision. A hydraulic pump or compressor alone can provide the necessary power for many different machines and their performance with different levels of power at one time, through hydraulic hoses. Hydraulic power machines can easily work in places where there is a flammable vapor or electrical or electronic equipment that may explode.
Hose classification: Hoses have a specific rating for their own types, which can be classified according to the type of fluid that they move, the temperature returns at which they work, and the amount of pressure they endure. Usually this information is printed on the hose or fittings. In some cases, a hose is printed with a model number and a technical data sheet is provided for a variety of models.
Caution: Hydraulic systems work to operate under high pressure machines. Hoses that do not operate at high pressures can impose a very strong impact (such as a flutter) on the surrounding area or on the operator’s hinges. Therefore, they should be checked and replaced at the right time, according to manufacturers’ recommendations.
High-pressure hydraulic fittings
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Use in oil industry, gas, petrochemical, shipbuilding, road building, airplanes, light and heavy machinery, industrial machinery, pumps, laboratory equipment, and installation of hydraulic lines and…
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Hydraulic
Types of hoses for different uses
Garden hoses are designed for water conveyance. Even in the garden hose category, there are many choices regarding material, size, length and type of connection.
Materials used in hoses
In terms of material type, there are basically two types of hoses:
*Vinyl hoses (plastic material made of polymer resin): Vinyl hoses are the most popular type of hose for homeowners because of their light weight, extremely easy to use and high variety.
*Rubber hoses: Rubber hoses are heavier, and are often considered by contractors and professionals. These hoses are used for long-lasting sessions. (Some hoses are also made up of two materials, commonly referred to as rubber-vinyl hoses).
Hose Features
For home use, there are a few things that should be considered in choosing a hose:
Hose length: In general, using a 50-feet hose can be used for all household purposes, such as to reach the front of the house to wash the car or to irrigate the gardens next to the house or the house yard. Hoses with a length greater than 75 and 100 feet are suitable for use in distant areas such as the back of the house or points away from the tap.
Hose diameter: As the most common hose diameter for home use is a diameter of 1.6 cm, professional contractors and professionals use hoses with a diameter of 1.9 inches that can handle more volumes of water in it takes a lot of time, but it’s a bit bigger and heavier for use.
Fittings: Most hoses that come to the market come with their fittings. They have a “pixel” at the bottom that connects the hose to the tap. At the other end, they have a “stingray” that can be connected to various devices such as sprayers. Fittings can be made of metal or rice. Metal or brass fittings can be made, depending on size, small to large and of various thicknesses. While there is a wide range of options for choosing the fittings, these fittings are usually matched to all valves and end fittings of the hoses.
Specialized hoses
There are a number of specialized hoses for specific uses, including:
An “absorbing hose” is a great choice for a warmer climate that can provide continuous moisture for plants and flowers in the open air. These hoses, which are usually made of porous rubber, allow the water to “slowly” permeate the hose. These hoods come in a wide range of sizes from 10 feet to 25 feet or even longer, which can be pulled along an area close to the roots of the plants, so that a continuous flow of Give them water.
Sprinkler hose: These hoses are often flat and at the ends of the needle are holes. They can be spread on lawns and areas to provide water.
Hot water hoses: Hoses must always be used to transfer water at ambient temperatures, and only hot hoses designed for hot water should be used for hot water.
Since most homes have tiny drips outside the house, and sometimes in garages, having more than one hose makes it easy and comfortable! The hoses can be placed in a hose pendant or in a hose reel for more order. A reel can protect the hose when it is not used in a way that is not visible. The use of a hose reel is particularly suitable for hoses longer than 50 feet long, making it easier to loop and assemble.
At the end of the season, the hose should be completely drained from the water, and looped regularly to increase its lifespan.
Hydraulic Hoses
Hydraulic hoses are made up of a number of rubber and thermoplastic layers. Cox is reinforced by wired coating with woven tape.
In Passen pressure, two-layer hoses with wired housings are used.
But at high pressures, hoses with a grid system that rejected these hoses instead of a wired network were used from four to six spiral layers of high resistance wires.
Hydraulic hose pressure:
According to the immune criteria, they are designed to have a burst pressure of more than three times the working pressure. Of course, the actual burst pressure is higher than this.
Hoses installation
Although assemble of hoses are considered simple, they need to be careful and creative.
* Avoid hose bending and torsion during installation.
* Hoses must be installed in such a way that they do not touch each other with other metal parts.
* Select the correct binding type.
Hose Disabilities
The hose’s disability is far from being expected, hoses usually have a builder’s code, a history of the groom, and the date of manufacture. The life of the hose depends on the working environment and the way it is used, and it can be accurately predicted.
The recurrent failure of the hose at a specific point in the circuit represents a mistake in choosing the type of hose and how it is mounted.
In brief, for hoses and fittings, we need to consider the following:
* Must be compatible with work fluid.
* It must have the ability to withstand volatility of the circuit pressure and shock wave resulting from these fluctuations.
* It must be resistant to fluctuations in fluid temperature and environment.
* In choosing the dimensions of the hoses and fittings, care must be taken to minimize the pressure drop and prevent damage caused by high turbulence and heat build-up.
* Make sure the hose connections are selected according to the hose. When installing the fittings, you must observe the assembly notes and, if necessary, use special tools according to the manufacturer’s recommendations.
* Hoses must be installed in such a way as to prevent sharp bending, twisting, bending, flattening, wearing and pulling in them. It should be noted that the length of the hoses is reduced by approximately 4% due to the pressure applied.
* Environmental conditions such as fog light, ozone, chemicals, salt water, solvents, corrosive liquids and air pollution affect the life of the hose.
* In some applications, the hose body should be an electrical conductor so that static electricity can be discharged due to the movement of some of the fluid in the hose.
Hoses according to their type of tissue are divided into three categories:
* Low pressure hose, up to 30 bars
* High pressure hose, up to 200 bars
* High pressure hose, up to 1300 times
Hub Casings:
* Occurrence of seasonal drop in tubes and oscillations
* Wrong pipe and hose selection (discharge cross-pressure – pressure bearing)
* A large maze in the pipe and hose (pressure drop)
* The use of unstable fittings in pipes and hoses
* Stretch and complexity in hoses
Head hose fittings:
For connecting the head of the hose to the orbits, the pipes are rigid and different connections are used, these connections are divided into two major types of mold connections and reusable fittings. In molded joints, for the connection of the hydraulic or mechanical molding machine is used. For the second kind of connections, you have to use simple tools.
Hydraulic hoses
*Design of lines under oil pressure
Calculation, design and selection of hoses for hydraulic systems require sufficient knowledge and experience. If you need to design these lines as a mechanical engineer, it’s best to give it to the experts in the hydraulic industry.
But if you are interested in designing and choosing a variety of hydraulic hoses, you need to study some practical reference in this regard.
The advice of all hose makers is that without the proper information and experience, you will never choose a hose, pipe, or hydraulic fittings.
*The information we need to know about hydraulic hoses
*Hoses are commonly used in both high pressure and low pressure groups. The low pressure hoses are fitted as a transparent rubber hose between the tank and the pump in the suction line, in addition to the oil transfer, the pump is free to vibrate. If the pipe is used in this situation, it is necessary to use a shaker in the pipe path.
*Low-pressure plastic hoses can also be used to transfer oil back from the port of leakage of valves and hydro motors.
*Hydraulic hose
*High pressure hoses, which are much more flexible than tubes, are used between fixed and moving parts. These components are mostly used in cases where rigid tubes cannot be used. One of the most important characteristics of hoses is to vibrate system and noise.
*Hoses usually consist of several layers.
The first layer is a rubber tire made of synthetic rubber, Teflon or polyester.
The second layer is an intermediate layer that has the task of bearing pressure and is usually made of a welded wire mesh made of steel strands and may be formed from several layers depending on the pressure to be tolerated by the hose.
The third layer, which is the highest layer, is made of abrasion resistant rubber such as polyester. This layer of hose may also be constructed in layers to protect against mechanical damage, from a layer to six layers.
Different layers of hydraulic hose
Main Properties of Hoses:
*Hydraulic hose
*Maximum permissible operating pressure: Generally this pressure is determined by the manufacturer, taking into account the static and dynamic pressures. The static working pressure is determined by a 1: 4 confidence coefficient, which is a maximum working pressure of 1/4 of the hose explosion pressure.
*Blast pressure: This pressure is usually determined by the test. The hose will not leak at the set pressure, and will not explode.
*Test Pressure: The hose is pressurized for a period of 30 or 60 seconds equal to twice the working pressure allowed to measure the hose strength.
*Increase in length: In all hoses, increasing length of pressure is observed. The amount of this variation is proportional to the design of their woven inner layers.
Bending radius: To maintain the safety of the hose function, the bend should not exceed a certain amount.
*Working temperature: The high operating temperature dramatically reduces the life of the hose.
Connecting presses
Lid connections are connected to either the inner thread or the outer thread to the next connections or system ports.
Types of fittings
*Size of hydraulic hoses
In two-layer hoses, the inner diameter with the outer diameter of the tube is also large, and its numerical value is exactly equivalent to the given number per inch. For example, the inner diameter of a 1.2 inch hose is exactly 0.5 inches, equivalent to 12.7. The outer diameter of the 1.2-inch tube is the same.
Comparison of Hoses and Tubes
The following table shows the sizes of the internal diameter of the common industrial hoses:
*How to install hoses
When installing hoses, it is necessary to pay attention to the points in the table below. The most important thing in installing a hose is to observe the appropriate length for it. Various parts should be able to move without pulling the hose. Also, the bend radius should be large enough.
Harness the hoses by hinging and installing the hinge
Hydraulic joints or hydraulic hoses: Fittings used to connect hydraulic hoses or hydraulic pipes to each other or to machines and machines, and these fittings, usually designed as males and materials, are leaking or Materials that are conveyed by pipes and hydraulic hoses and high pressure are prevented.
Hydraulic joints or hoses are usually made of steel or stainless steel, rice or aluminum, and usually their outer layer is zinc or nickel plated and hardened. Their working pressure is up to 1200 times.
Joints are in the form of a cardiac or brain, mediator, knee, three ways, intersection, flange, shell, and so on.
Various types of connections are used in relevant systems around the world, and this variation results from national or international standards or the specific requirements of a client or a market.
But the most important connections in terms of geometric shape and gear include: American, English, German and Japanese.
The NPTFs are National Pipe Tapered Fuel, which include JIC, ORFS gear and more.
The English Gear BSP is abbreviated to British Standard Pipe and includes BSPT and more.
German Gears Metric
Japanese gears JIC is abbreviated as Japanese Industrial Standard.
Oil and wind coupling
Hoses, fittings, presses and hoses are ready to provide services to companies, factories and industrial machinery, and supply and equipment’s for hydraulic, pneumatic, petrochemical, steam, water, etc.
About hydraulics
The development of hydraulic science began when the French scientist Pascal discovered pressure laws (1650 AD) and founded hydraulic as a new science. From that date onward, a period of hydraulic flood emerged, and this science has entered the market dramatically. Nowadays, hydraulic in the building of industrial machinery, agriculture, road construction, aircraft, shipbuilding, automation, utility machines, heavy industry, mining and others. . . It is used on a large scale and increases day by day.
Hydraulics is the technology of producing, controlling and transferring power by fluid pressure. In general, a hydraulic system carries out four basic tasks:
*Conversion of mechanical energy to fluid pressure under pressure by pumps
*Move the fluid to the points you want by pipes and hoses
*Control of pressure, direction and flow of fluids by valves
*Perform work by operators
Pascal’s Law:
The Pascal Act is the new hydraulic principle. This law states that the pressure applied to any point of a finite liquid is equally transmitted in all directions and equally effective on equal levels.
Basic Hydraulic Rules:
*Under pressure, the fluid always chooses a path with less resistance to passage
*The pump produces a discharge, not pressure
*Pressure is created only against the resistance of an obstacle
The key principles, although simple, seem to be based on the science of hydraulics. With the correct understanding of these rules, it is easy to follow the flow of fluid in the transmission lines and analyze the performance of the system.
Information on hydraulic hoses
Calculation, design and selection of hoses for hydraulic systems require a high level of knowledge and experience in this field. If you need to design these lines as a mechanical engineer, you should even send it to the experts of the hydraulic industry.
However, if you are personally interested in designing and choosing a variety of hydraulic hoses, you need to read at least some practical reference in this regard.
The strong recommendation of all hose makers is to never choose a hose without enough knowledge and experience.
Hoses are usually used in two groups of high pressure and low pressure. Low pressure hoses are fitted as a transparent spring hose between the tank and the pump in the suction line, in addition to the oil transfer, the pump may be free to vibrate. In case of using the pipe in this position, it is necessary to use a shaker in the pipe path.
Low-pressure plastic hoses can also be used to transfer oil back from the leakage port of the valves and to the hydro motors.
Hydraulic hoses
High pressure hoses, which are much more flexible than tubes, are used between fixed and moving parts. These components are most often used in cases where rigid tubes and tubes cannot be used. One of the important features of hoses is the mitigation of system vibration and noise.
Hoses are usually made up of several layers. The first layer is rubber tubing made of synthetic rubber, Teflon or polyester. The middle layer, which has the task of bearing pressure, is usually made of a wired wire mesh made of steel strands. Due to the pressure to be tolerated by the hose, this section may be composed of several different layers. The third layer, the highest layer, is made of abrasion-resistant rubber such as polyester. This layer of hose may also be made to protect against mechanical damage in layers, from a layer to six layers.
Pneumatic fittings, Pneumatic valves, Care units, Blowers and Cylinders
Hydraulic & Pneumatic, Hoses & Fittings (CEJN) Sweden, Kaiser
1-Providing hydraulic couplings with carbon steel material, rice, stainless steel, with Germany’s Kaiser brands, American Parker, Apian Italia, Stable France, Rectus Germany, Tweed Sweden and CE (Swedish CEJN) and Walter Germany WALTER Lap series -MD-HP
2- Providing pneumatic couplings with carbon steel material, rice, stainless steel with Kaiser Germany brands, American Parker, Apian Italia, Stable France, Rectus Germany, Swedish (CEJN) Sweden
3-Provision of cooling couplings of various types of industrial molds with rice material, stainless steel with Germany’s Kaiser Brands, Apian Italy, and Stable France
4-Provision of test couplings for road vehicles, Komatsu, loader and … for pressure testing with CEJN Sweden and TEMA (TAM) Sweden
5-Providing TEST POINT fittings, hoses and manometers to pressure the brand STAUFF Germany and MCS Italy
6-Supplying high pressure valves and valves (ultra High Pressure) 1000 bar -1500 bar-2000 bar- 2500 bar 3000 bar with CEJN Sweden
7-Providing Parker’s high pressure fittings and pneumatic fittings with FESTO brands in Germany and AIGNEP Italy
8-Provide respiratory hoses RECTUS Germany and CEJN Sweden
9-Supplying and manufacturing of welded hose hoses, elastic hoses, flexion hoses, stainless steel Teflon hoses up to 2500 bar, food hoses, steam hoses (STEAM) and Teflon
10- Supply of silicon glass fiber and aluminum coatings
11-Provide PU (Polyurethane) and PA (Polyamide) PTFE Hoses (Teflon)
12-Providing pneumatic fittings and nozzles of cement factories
13-Supply of valves and valves for industrial machines
14-Supply of steel hydraulics and copper pipes
15-Supply of electric valves, pneumatic jacks, and care units (L.R.F) Filter + Regulator + Oil
In this regard, it also cooperates with organizations such as cement, steel, textile, printing, automotive, instrumentation, aviation, food industry (milk, ice cream, soft drinks, etc.).
If possible, visit the business unit to provide the necessary ground for starting the cooperation.
Flexible fittings for pipelines and ducts, including Marin’s pipes, fabric fittings, accordion joints, rubber shrinkage vibration.
Basic pneumatic information
Pneumatic
Today, in many industrial processes, power transmission is considered low cost and with high precision. In this regard, the use of pressure fluid in the transmission and control of power in all branches of the industry is expanding. The use of fluid power is divided into two important hydraulic and pneumatic branches.
Pneumatic systems are used in cases where relatively low forces (about one ton) and high motor velocities are needed (such as those used in belt actuators), while the applications of hydraulic systems are mainly in those cases where high powers and speeds Controlled precision (such as hydraulic jacks, brakes and hydraulic steering, etc.)
The question now is that the benefits of a pneumatic system to other mechanical or electrical systems are:
*Simple design
*Increased power
*Simplicity and precision control
*Flexibility
*High efficiency
6 Reliability In the pneumatic system, there are fewer actuator parts than other mechanical systems, and high-power, high-speed linear transients and proper control can be achieved at any point, because the power transfer by high-pressure fluid flow in the transmission lines (pipes and hoses), But in other mechanical systems, they use components such as cam, gear, car, lever, clutch, and so on.
In these systems, it can be achieved by applying a low force to the high and precise force. Also, large output forces can be controlled by applying a small force (such as the valve closing the valves, etc.).
The use of flexible hoses turns the pneumatic system into flexible systems that do not have the space constraints for installing other systems. The pneumatic system has high efficiency due to its low friction and low cost. Also, using safety valves and pressure and heat switches, it is possible to build a system resistant to sudden loads, heat or pressure, which indicates the high reliability of these systems. .
Now that we understand the advantages of the pneumatic system, we will give a simple explanation of how these systems work.
In order to transfer power to a pressurized (compressible) fluid, we need mechanical pressure to convert the mechanical force into a fluid (pneumatic) pump (compressor). The next step is to transfer the force to the desired point, which assumes the responsibility of pipes, hoses and fasteners.
After controlling the pressure and determining the flow direction by the valves, the fluid is directed to the operators (cylinders) under pressure to convert the fluid’s strength to the required mechanical force (linear or rotational).
The basis of all pneumatic systems is based on Pascal’s law.
Pascal’s Law
*The pressure is constant throughout the remaining fluid (regardless of the weight of the fluid)
*At any given time, the static pressure is the same in all directions.
*The fluid pressure is brought into contact with the surfaces vertically.
The operation of pneumatic systems is similar to that of hydraulic systems, only using compressible fluid such as air instead of an incompressible fluid such as oil. In pneumatic systems, to reach a high pressure fluid, the compressed air is compressed by a compressor to reach the desired pressure and then stored in a reservoir, although the air temperature is very high after compression, which can damage the damaged parts Therefore, compressed air must be cooled down before conducting to power transmission lines. Due to the presence of vapor in compressed air and the condensation phenomenon in the cooling process, an optimization unit should be used to dry the high pressure air.
Now, after a brief introduction to the operating procedures of pneumatic systems, we introduce the components of a pneumatic system.
Components of pneumatic systems
*Compressor
*Cooling and drying pressurized air
*Pressurized air reservoir
*Control valves
*Operators
A general comparison between hydraulic and pneumatic systems
*In pneumatic systems, compressible fluid such as air and in hydraulic systems uses an incompressible fluid such as oil.
In hydraulic systems, the oil in addition to the transfer of power also serves the lubrication of the internal parts of the system, but in pneumatics, in addition to the lubrication of parts, the moisture content of the air should be eliminated, but in both systems, the fluid should be free of any Dust and unclean species
*Pressure in hydraulic systems is much more than pneumatic pressure, even at specific times, reaches 1,000 MPs, so the parts of the hydraulic systems should be more resistant.
*At low speeds, the precision of pneumatic actuators is very unfavorable if the precision of the hydraulic actuators is satisfactory at any speed.
*In pneumatic systems with air fluid, no recirculation tubes or air storage tank are required.
Hydraulic fittings
1-Types of Fitting, Stainless Steel Fiberglass Flaps, Pneumatic Hydraulic Hoses, Special Hoses for Chemicals, Industrial Petroleum with Related Fittings, 1350bar, Carbon Steel, Stainless Steel, Galvanized Steel, Bronze, Aluminum, Venice, All Valves.
Mother industries, including the fields of oil, gas, petrochemicals, machinery, steel, cement, shipbuilding, ceramic tiles, take a step further.
Steel companies – Drilling companies – Petrochemical and petrochemical complexes – Machinery manufacturing companies – Automobile companies – Shipbuilding – Dam construction companies – Road construction companies – Rail transport – Cement and rubber companies ….
Hydraulic hoses
Hydraulic pipes and hoses are used to move fluid from point to point and serve as blood vessels for the human body.
The following factors can be applied to increase fluid flow.
1- Increase drain factor (decrease in friction in the pipe); Also, use of pipes having a uniform cross-section.
2-In order to increase the hydraulic transmission, it can increase the pressure inside the circuit. In proportion to the pressure increase in the hydraulic circuit, pipes or hoses are used. In hydraulic systems, more reactive hydraulic hoses are used instead of steel pipes. Gets
1- Hydraulic circuit-breaker changes: In hydraulic oil hoses, the formation of compressive waves (Toc’s) during the pressure changes in the hydraulic hoses creates fatigue. Considering the aforementioned, the hydraulic hoses are first in front of Strong pressure, secondly, is resistant to fatigue. Thirdly, it increases its elasticity, which can be a blow to it.
2- The location of the steel pipes in the lower connections of hydraulic hoses. Meanwhile, hydraulic hoses have full degrees of freedom, which is in the steel tubes.
Physical Properties of Hydraulic Hoses
1) Resistance to pressure and pressure variations
2) Resistance to fatigue
3) Resistance to changeable shape
4) Resistance to temperature changes (at high temperatures causes excessive burnout of hoses)
5) High thermal transfer coefficient
6) Failure to lose quality and to be mechanized
7) Resistance to chemical corrosion of oil
Hydraulic hose building
Due to the low resistance of rubber in hydraulic hoses, hydraulic hoses are reinforced with tufted fibers. These tufted fibers are made of thin steel wires with thicknesses of 0.003 to 0.006 mm in diameter, which are honeycomb in networks Taken equally well used. Also, for greater flexibility, steel layers are made of synthetic tufted fibers that increase resistance to hose fatigue.
Therefore, the hose is internally sealed to resist a heat resistant rubber that is made of synthetic leather and in the outer part to protect the layers against the vulnerability of the rubber. The entire rubber sheathing inside and outside is a volatile rubber that has not been cooked.
The inner layer is made from cooked oil that is resistant to heat and is made of synthetic leather. It prevents hydraulic leakage if the oil can penetrate into the rubber tube. Gradually due to the strength of the time the tube will be destroyed and its resistance to heat will be reduced. The next layer is a woven fabric that is used in standard wire diameters and can be from 0.6-0.3 mm or 24% in diameter, depending on the application. This woven fabric enables rubber tubes to withstand high pressures and also protects against external destructive effects. The hollow only has a wired rope, it is called a single-walled fabric, and if there are two rows covered, they are wire-wired. The wires are double-woven. As the number of wired layers increases, the hose strength will be higher than the pressure. And these layers will be very effective in the life of the hose.
The wires used in the woven fabric are woven crosswise and have a good angle to withstand a high pressure. Therefore, in successive bending or twisting of hoses, the angle of the diagonal tissues changes relative to each other and as a result the strength of the resistance the hose is reduced against the pressure, where it will rupture. Wire harness is protected by a rubber coating against external destructive effects. In some types of hoses, a hollow tube surrounds the outside of the hose to the hose is protected by possible hazards such as rock falls and so on.
The high pressure hose described here is known as a woven wire hose, and there is another type of hose construction that is called a spiral hinge and the same is the same. In a spiral hose, two rows in all directions, in opposite directions, the wire is wound around the rubber tube.
Important notes on the use of hydraulic hoses
1-Temperature control in the hydraulic circuit (using a suitable oil cooler) The operating temperature in the hydraulic circuit is about 80 degrees centigrade and 176 degrees Fahrenheit, which can be increased by a cross sectional temperature of up to 100 centimeters.
2-Due to the fact that oils lose their physical and chemical properties at temperatures above 110 ° C, they must be replaced in order to avoid damage to the hydraulic circuit.
3 – Use suitable hose with sufficient strength
4 – The system eliminates the impact loads in a hydraulic circuit that prevents sudden pressure changes in the hose.
5 – Hydraulic hoses should not be exposed to sunlight. (Environmental conditions)
Important notes about installing hydraulic hoses
1 – Selection of suitable hydraulic hose (in accordance with working conditions)
2 – Can be used for length.
3-Selecting the appropriate cross-section hose (especially in loader and grader casings, in both ends of the cup, the cross-section of the hose must be equal; otherwise, the blade can break.
4-Avoid excessive twists.
5- Use a suitable hose.
Hydraulic hose replacement time
1) Holding or leakage of hoses and hydraulic connections
2) Curvature and incision of the hose cover or appearance of the wiring hinge reinforcement layers
3) Inflate various hose locations
4) Screw or wound moving points
5) Insert external parts in the layer on the hose
In the field of oil, gas, petrochemicals, light industry and facilities.
*Instrumentation:
Pressure regulators, pressure fittings, valves and manifolds, pressure and temperature gauges, solenoid valves and pneumatic equipment.
*Valve Process Includes:
Gate Valve, Globe Valve, Butterfly Milk, and One-way Valve from 1.4 inches to 42 inches in steel, stainless steel and special alloys, electro-pneumatic, pneumatic and manual.
*Pipes and fittings include:
Seamless and seamless pipes in sizes from 1.8 to 56 inches made of steel, stainless steel or special alloy and titanium
Boiler tubes (seamless and seamless), cast iron fittings, alloys, stainless steel and titanium
Seamless and seamless pipes for chemical and petrochemical industries
Finishing pipes, knees and special fittings for casting and stretching
Ceramic alloy pipes, heat resistant and produced by centrifugal casting
Joints and parts for boilers in all sizes
All joints (thread and weld) made of steel, stainless steel and special alloys with ANSI, API, BS, DIN, MSS,
*Filtration systems:
Fuel filters and water filters, filters, process filters Food Standards FDA, air filter compression of gases, filters, high pressure gas, CNG, hydraulic filters, oil filters, filter bags, filter activated charcoal, ceramic filter, dust filter and Oil particles.
Fittings and hoses:
All hydraulic, industrial and high pressure fittings, thermo plastic hoses, hose cutting and hose couplings, quick couplings and combinations
*Sensors and measuring equipment:
Transmitter types, Positions, Gauges, Calibrators, Transducers, Sensors, Flow meters, Analyzers, Level sensors, Regulators, Air distribution manifolds, Siphon probes, Probes, Orifice and Compressor level switches, Oscilloscopes, Voltage sources, Clock configurations , Noise Sensors, Types of Tester Types and Test Gauges.
*Other equipment includes:
Types of nitrogen devices, various types of water desalination devices (RO) and their equipment, plate heat exchangers and cookers, types of AC / DC drives, bolts and nuts, types of gaskets and oaring, industrial tools, solvents And adhesives, anti-corrosion materials and …
Hydraulic, Pneumatic and Instrumentation of Oil, Gas, Steel, Cement, Petrochemical, Automotive, Road Construction, Damping, Machine, Electric, Construction and Related Industries.