The maintenance of stainless steel ball valves generally has the following steps:
1. Blow the outer surface of the stainless steel ball valve with compressed air.
2. Check and write down the marks on the stainless steel ball valve.
3. Disassemble all the stainless steel ball valves.
4. Clean the parts with kerosene.
5. Check parts for defects.
(1) Check the strength of the valve body by hydrostatic test.
(2) Check the cooperation between the valve seat and the valve body, as well as the closing parts and the sealing ring, and conduct a tightness test.
(3) Check the thread wear of the stem and stem bushing.
(4) Check the sealing ring of the closing member and the valve body.
(5) Inspect the flange joint surface.
6. Repair the valve body.
(1) Weld repair defects and replace sealing rings or surfacing sealing surfaces.
(2) For the valve body and the newly replaced sealing ring, an air tightness test should be carried out.
(3) Trim the flange joint surface.
(4) Grinding the sealing surface.
7. Repair the closure.
(1) Welding repair defects.
(2) Overlay welding sealing surface.
(3) Polish or grind the sealing surface.
8. Replace the irreparable parts.
9. Reassemble the stainless steel ball valve.
10. Carry out the overall hydrostatic test.
11. Paint and mark according to the original record.