In the industrial system, we often see a variety of hydraulic valves, it is one of the indispensable components of the system, now the market production of valve manufacturers more and more, we often come into contact with the hydraulic system in our lives often see a variety of hydraulic valves, so what are the connection methods of hydraulic valves? How to choose the connection mode of hydraulic valve?
01
Connection mode of hydraulic valve
1. Threaded connection
The valve with a thread on the oil port of the body is called a tubular valve. The oil port of the tubular valve is connected to the pipeline with a threaded pipe joint and thus fixed on the pipeline.
2. Flange connection
Through the screw holes on the valve body (more than 4 screw holes per oil port) and the flange of the end of the pipe fitting, the valve connected together with screws is called flange-connected valve.
3. Plate connection
Each oil port of the valve is arranged on the same installation plane, and there is a connection screw hole, this valve is called a plate valve, such as the electromagnetic reversing valve is mostly a plate valve. Screw the plate valve to the plate type or valve block type connection body with the corresponding oil port of the valve.
The connecting body connected with the plate valve has two forms of connecting plate and integrated block:
Connecting plate. The plate valve is fixed on the connecting plate, and the oil circuit between the valves is connected to the pipe with a pipe joint behind the plate.
Integration block. The integrated block is a regular hexahedral connector. The plate valve is fixed to the three sides of the block with screws, and sometimes a simple valve can be installed between the valve and the block with a pad. The remaining side is fitted with tubing to connect the actuator. The upper and lower part of the integrated block is the joint surface of the block and the block, and the common oil through holes are drilled in the vertical direction of the same coordinate position on the joint surface of each integrated block: pressure oil hole P, oil return hole, oil leakage hole L, installation bolt hole, and sometimes the jade oil road hole. Punch holes in the integrated block and communicate each valve to form a loop. Each integrated block and the valve type components installed around it constitute an integrated block group, and each integrated block group is a typical loop.
4. Superimposed connection
The upper and lower parts of various hydraulic valves are made into a connection surface like the bottom surface of the plate valve. In the connection surface of various hydraulic valves of the same specifications, the position of the oil port, the position of the screw hole, and the connection size are the same (determined by the connection size of the reversing valve of the same specifications), this valve is called the superposition valve. According to the requirements of the system, superposition valves with various functions of the same specifications can be stacked in a certain order to form a superposition valve type hydraulic device.
The bottom of the superimposed valve type hydraulic device is generally A bottom plate, which is provided with an oil inlet P, an oil return port T, and an oil port A and B leading to the actuator and a pressure gauge oil port.
A stack valve group generally controls an actuator. If there are several actuator groups in the system that need to be centrally controlled, several vertical stack valve groups can be placed side by side on a multi-plate.
5. Plug-in connection
The valve is made into (without the valve body) cylindrical special components one by one. A hydraulic system is formed by inserting the cartridge directly into the socket hole of the valve block (integrated block) with a perforated channel. All kinds of pressure valves, flow valves, direction valves, proportional valves, etc., can be made into cartridge valves.
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02
Advantages and disadvantages of various connection methods
1. Threaded connection, flange connection
The advantages are: simple connection, convenient layout, the oil circuit between the valves in the system is clear.
The disadvantages are: scattered components, occupy a large space, pipeline interleaving, many joints, not easy to load and unload maintenance.
2. Plate connection
The advantages are: easy replacement of components, does not affect the pipeline, and it is possible to centrally arrange the valve. The connection body is an integrated block, which has the advantages of compact structure, small footprint, easy loading and unloading and maintenance, and can simplify the design of hydraulic system into the selection of integrated blocks.
The disadvantages are: the design workload is large, the processing is complex, and the system cannot be modified at will.
3. Superimposed connection
The hydraulic system composed of superposition valve, the connection between the components does not use pipes, nor does it use other forms of connection, so the structure is compact, small size, the leakage loss and pressure loss of the system is small, especially the hydraulic system is more convenient and flexible to change, the superposition valve is a standardized component, the design only needs to draw the superposition valve hydraulic system schematic diagram, you can be assembled. Therefore, the design workload is small.
4. Plug-in connection
The advantages are: the structure is very compact, all kinds of pressure valves, flow valves, direction valves, proportional valves, etc., can be made into cartridge valves.
03
Hydraulic valve connection mode selection
The following factors need to be considered when selecting the connection method of the hydraulic valve:
1. System pressure: System pressure is an important factor in choosing the connection method of hydraulic valve. Pipe connections and plate connections are suitable for low system pressure situations, while integrated block connections and stack valve connections are suitable for high system pressure situations.
2. Oil circuit layout: Different connection modes can be selected according to the requirements of oil circuit layout. For example, pipe connections have a more flexible oil circuit layout, while plate connections have a more compact oil circuit layout. Please refer to:
When the working flow of the hydraulic system is below 100L/min, the stack valve can be preferred, which will greatly reduce the number of oil circuit blocks, thus reducing the volume of the system;
When the working flow of the hydraulic system is more than 200L/min, the plug-in connection valve can be given priority to use, and a series of advantages of the plug-in valve can be fully utilized;
When the working flow of the hydraulic system is 100-200L/min, the priority order should be ordinary valves, superimposed valves, and cartridge valves.
3. Maintenance convenience: Maintenance convenience is also an important factor in choosing the connection method. Tube connections and plate connections are relatively easy to maintain, while integrated block connections and additive-mode connections are relatively difficult to maintain.
4. Reliability: When selecting the connection method of the hydraulic valve, it is necessary to consider its reliability. The reliability of pipe connection and plate connection is high, while the reliability of integrated block connection and stack valve connection is relatively low.
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5. Economy: Under the premise of meeting the requirements of the system, the connection method with better economy should be selected. The cost of tube and plate connections is relatively low, while the cost of integrated block connections and stack valve connections is relatively high.
