What are the precautions to avoid during the production of superimposed relief valves

During the production process of the superimposed relief valve, in order to ensure its stable performance, safety and reliability, special attention should be paid to the following matters to avoid potential problems:

1. Precautions for structural design

Avoid excessive internal volume: If the internal volume of the remote control control pipeline is large, it may cause vibration. It is recommended to use pipes with an inner diameter of less than 4mm and control the length to less than 3 meters to reduce the risk of vibration.

Ensure the independence of the oil circuit: Direct-acting and remote-controlled relief valves must not be connected to the oil return pipes of other types of valves. The oil return pipe must be directly connected to the oil tank to prevent oil circuit interference and unstable performance.

Optimize the cooperation between pilot valve and main valve: The pilot valve must adopt a conical valve structure, and the main valve core should be designed as a one-way valve-type secondary concentric structure to achieve stable pressure adjustment through precise coordination.

2. Material selection and sealing requirements

Strictly screen sealing materials: O-ring and other seals must be oil-resistant and wear-resistant materials, and ensure that the hardness complies with JISB2401 standards to prevent leakage due to material aging.

Control the sealing surface accuracy: The sealing surface roughness must be controlled within Ra0.8μm to ensure the sealing effect and avoid external leakage caused by surface defects.

3. Key points of assembly process

Standard installation direction: In principle, superimposed valves should be installed vertically to avoid horizontal installation causing the bolt to be deformed by gravity, which will cause oil leakage between the valves.

Unified diameter and connection size: The diameter specifications of the reversing valves, superimposed valves and bottom plates in the same circuit must be consistent, and strictly follow the ISO 4401 standard to prevent oil circuit from being misaligned or leaked.

Stage-tightening bolts: Use special tools to tighten the installation bolts in stages according to standard torque, and tighten them after trial operation to ensure reliable sealing between the valve bodies.

4. Pressure regulation and testing specifications

Follow the adjustment direction: adjust the pressure regulating handle clockwise and adjust counterclockwise when the pressure is reduced. After the adjustment is completed, the fixing nut must be locked to prevent pressure drift.

Avoid resonance: It is prohibited to use two relief valves with the same specifications and setting parameters in parallel to prevent noise and pressure fluctuations caused by resonance.

Strictly test the opening and closing characteristics: test the opening and closing process through the data acquisition system or record point-based method to ensure that the pressure changes are stable and there is no sudden jump.

5. Adaptive design of the use environment

Control the back pressure of the return oil circuit: The minimum adjustment pressure must be equal to the sum of the minimum adjustment pressure characteristic value and the back pressure at the valve outlet to avoid performance degradation due to excessive back pressure.

Adapted to high-pressure systems: If used in high-pressure systems, a pilot type relief valve must be selected and the diameter of the main valve core damping hole is optimized to prevent slow movement or hydraulic impact.

Prevent leakage from the remote control port: The hydraulic components connected to the remote control port must be made of a model with a small leakage amount to avoid the system pressure not reaching the set value due to leakage.