Preventive Measures Of Hydraulic System Leakage(3)

1. To assemble the sealing ring correctly

When assembling the sealing ring, oil should be applied to its surface. If it is necessary to pass the key way, thread and other openings on the shaft, guide tools should be used instead of metal tools such as screwdrivers, otherwise the sealing ring will be scratched and oil leakage will occur. For directional sealing rings (such as V, Y and Yx type sealing rings), the lip should be facing the pressure oil chamber during assembly, and care should be taken to protect the lip and avoid being scratched by sharp edges and burrs of parts. For the sealing surface that is in contact with rotation (such as the shaft end of the driving gear of the hydraulic pump), a double-lip sealing ring should be used. Before installing the combined seal, the seal should be boiled in hydraulic oil to a certain temperature; the special guide sleeve and closing tool should be used during installation, and the manufacturer's installation instructions for the seal should be strictly followed.

2. Control oil temperature to prevent seal deterioration

An important cause of premature seal deterioration is excessive oil temperature. In most cases, when the oil temperature often exceeds 60 ℃, the viscosity of the oil drops greatly, and the sealing ring expands, ages, and fails, resulting in leakage of the hydraulic system. According to research, the life of the seal will be halved every time the oil temperature rises by 10°C, so the oil temperature should be controlled within 65°C. To this end, the oil outlet pipe and the oil return pipe inside the oil tank should be separated by a partition to reduce the distance between the oil tank and the actuator (cylinder or hydraulic motor), and use as few right-angle elbows as possible on the pipeline; For the compatibility of sealing materials, the type and material of hydraulic oil and seals must be selected according to the instruction manual or relevant manuals.

3. Pay attention to repair and assembly process

The repair process for leak prevention and control should be strengthened. For example, the whole or part of the valve stem, the surface of the piston, and the inner wall of the hydraulic cylinder can be thickened by brush plating and electrostatic spraying, and then machined to the required size by a lathe. When installing threaded fittings, teflon tape should be wrapped around the threads. Flaw detection and pressure test should be carried out for castings or welded parts before installation. The pressure of the pressure test is equivalent to 150% to 200% of its maximum working pressure. When the oil is sealed into the seat hole, it should be introduced with a special tool to prevent position deviation.