Reasons and elimination methods for knife gate valve failure

Packing leakage

1. The packing gland is not tightly pressed

2. The filling material becomes ineffective due to prolonged use or improper storage

1. Tighten the nut evenly and tighten the packing tightly

2. Replace the packing

Leakage between sealing surfaces

1. There are dirt and debris adhering to the sealing surface

2. Damaged sealing surface

1. Clean up the dirt and debris. 2. Reprocess, repair or replace

Leakage at the connection between the valve body and the valve cover

1. Uneven tightening of connecting bolts

2. Damaged flange sealing surface

1. Tighten evenly

2. Reshaping

The handwheel does not rotate flexibly or the gate cannot be opened or closed

1. The packing is pressed too tightly

2. The valve stem nut is damaged

3. The thread of the valve stem nut is severely worn or broken

4. Valve stem bending

1. Loosen the nut on the packing pressure plate appropriately

2. Disassemble and repair threads and remove dirt and debris

3. Replace the valve stem nut

4. Correct the valve stem