Common faults of gate valves and their solutions

October 10, 2018

Common faults of gate valves and their solutions

1. Leakage at the gate of the gate valve

  • The packing gland is too loose to evenly tighten the nut for the compression packing gland.
  • If the number of packing rings is not enough, the packing should be added.
  • Fillers should be replaced with new fillers due to excessive use or improper storage. When replacing, be careful that the joints between the rings should be staggered 1200.

2. Between the gate valve and the seat sealing surface

  • There is dirt between the sealing surfaces, which can be washed away.
  • If the sealing surface is damaged, it should be re-ground. If necessary, it can be re-welded and processed. The grinding sealing surface must be flat and its roughness should not be less than 0.4.

3. The leakage nut of the gate valve body and the bonnet joint is not tightly tightened or the tension is uneven, and can be re-adjusted.

  • Damage to the flange seal surface (straight grooves or grooves) should be corrected.
  • If the gasket is damaged, replace it with a new one.

4, gate valve stem drive is not flexible

  • If the packing is too tight, loosen the nut on the packing gland.
  • If the position of the packing gland is not correct and the valve stem is stuck, the nut on the packing gland should be evenly turned to return the gland to its normal position.
  • The threads on the stem and stem nut are damaged and should be removed after disassembly.