Notes on hydraulic components and installation tips

1. Hydraulic piping
(1) Select the oil pipe according to the pressure and the use occasion. The oil pipe must have sufficient strength, the inner wall should be smooth, clean, free of sand, rust, and oxide scale. For pipes that have been stored for a long time, they should be pickled, thoroughly cleaned and flushed before processing. , and check.
(2) When cutting the pipe with a saw, the non-perpendicularity of the section and the axis direction should be ±0.5°, the sharp edge must be blunt and the iron filings should be removed, and the ovality of the section is allowed to be 10% when processing the bent pipe. When the outer diameter is less than 14mm, hand and general tools can be used to Accumulator safety valve bend the pipe. For thicker steel pipes, manual or motorized pipe benders should be used to bend the pipes. Generally, the radius of the pipe should be three times larger than the outer diameter of the pipe.
(3) The requirements for installing the pipeline are that the line is the shortest, the turns should be as few as possible, and the highest part of the pipeline should be equipped with an exhaust device to allow the air to be released during startup.
(4) When installing the rubber hose, avoid sharp turns, and its bending radius R≥(9~10)D (D is the outer diameter of the hose). Do not bend near the root of the joint, and the distance from the hose joint to the beginning of the bend is required to be L≥6D. The hose should not be twisted while working.
(5) The oil suction pipe must not leak air, nor should the resistance be too large to prevent cavitation due to difficulty in air intake or oil absorption.
(6) The outlet of the oil return pipe must be extended below the oil level of the fuel tank to prevent splashing and generating air bubbles. The oil return pipe of the relief valve cannot be directly connected to the inlet of the pump, and must pass through the oil tank, otherwise the oil temperature will be too high.
(7) The installation procedure of all pipelines is carried out in two times. First, the trial assembly is carried out, and the pipe joints and flanges are spot welded in suitable positions.
2. Other hydraulic components
(1) All hydraulic components must be tested for pressure and sealing, and can only be installed after passing the test. Various automatic control instruments should be calibrated before installation to avoid mistakes.
(2) When installing various control valves, pay attention to the orientation of the oil inlet and the oil return port. When installing valve parts with flanges, the screws should not be over-tightened, as over-tightening may cause poor sealing.
(3) The installation of the hydraulic cylinder should be firm and reliable. In order to prevent the influence of thermal expansion, when the stroke is large and the temperature is high, one end of the cylinder must be kept floating. The sealing ring of the hydraulic cylinder should not be too tight, especially the U-shaped ring, so as to avoid excessive resistance.
(4) The deviation of the different axial degrees of the hydraulic pump drive shaft and the motor drive shaft should be less than 0.1mm. Generally, flexible couplings are used for connection. It is not allowed to directly drive the pump shaft to rotate with tape to prevent the pump shaft from being subjected to excessive radial force. large, affecting the normal operation of the pump.
(5) When installing the hydraulic pump, its rotation direction and the oil inlet and outlet should meet the technical requirements.
(6) The oil suction height of various hydraulic pumps is generally less than 0.5mm.
Installation Precautions:
(1) The performance level of the valve connecting screw must meet the requirements of the manufacturer, and must not be replaced at will. The connecting screws should be evenly tightened (do not hit with a hammer or forcibly twist), do not twist off, and finally make the installation plane of the valve and the bottom plate or oil block installation plane all in contact.
(2) Pay attention to the orientation of the oil inlet and the oil return port. For some valves, if the oil inlet and the oil return port are reversely installed, it will cause an accident. For the convenience of installation, some valve parts often have two holes with the same function, and the unused one should be blocked after installation.
(3) The installation method of the hydraulic valve shall comply with the requirements of the manufacturer and the system design drawings.
(4) The plate valve or cartridge valve must have correct orientation measures.
(5) In order to ensure safety, the installation of the valve must consider the influence of gravity, shock and vibration on the main parts in the valve.
(6) The directional valve should generally be installed with the axis horizontal;
(7) Generally, the valve parts (such as flow valve, pressure valve, etc.) that need to be adjusted, when rotating clockwise, increase the flow and pressure, and when rotating counterclockwise, reduce the flow and pressure.