Hydraulic system installation, debugging and maintenance (2)

Hydraulic system installation, debugging and maintenance (2)

5. The air filter is used to filter the dust in the air, and the ventilation resistance should not be too large to ensure that the pressure in the box is atmospheric pressure. Therefore, the air filter must have a large enough ability to pass air.

（C) Quality inspection of pipes and joints, the pressure level of pipe joints should meet the design requirements

（a) The material, diameter, wall thickness of the pipe, the model specification and processing quality of the joint must meet the design requirements. 

（b) The tubes used must not be defective. The following exceptions are not allowed to be used:

1. The inner and outer wall surfaces of the pipe have been corroded or have significant discoloration. 

2. The depth of the wound and crack on the surface of the tube is more than 10% of the wall thickness of the tube. 

3. There are small holes in the pipe wall. 

4. The concave degree of the pipe surface reaches more than 10% of the pipe diameter.

（c) When using curved pipes, the following exceptions are not allowed:

1. Irregular or zigzag curve on the inner and outer wall surface of the pipe bending part. 

2. The ellipticity of the bending part of the pipe is more than 10%. 

3. The minimum outer diameter of the flat bending part is less than 70% of the original pipe outer diameter.

（d) The joints used must not be defective. If there are the following abnormalities, it is not allowed to use:

1. There are scars, burrs or broken buckles on the thread of the joint body or the nut. 

2. The machining accuracy of each joint surface of the joint body does not meet the technical requirements. 

3. The joint body and the nut are not well matched, and there is looseness or jamming. 

4. The groove size and machining accuracy of the sealing ring have not reached the specified technical requirements.

（e) Flexible hoses and joints with the following defects are not allowed to be used:

1. There is skin damage or aging on the surface of the hose. 

2. The joint body is corroded. 

3. The thread has scars, burrs, broken buckles and loosening and jamming.

（f) Flange parts are not allowed to be used if they have the following defects:

1. There are pores, cracks, burrs and radial grooves on the flange sealing surface. 

2. The size and processing accuracy of the flange sealing groove do not meet the design requirements. 

3. The sealing metal gasket on the flange is not allowed to have various defects. The material hardness should be lower than the flange hardness.