Common Faults and Troubleshooting of Non-Rising Stem Resilient Seated Gate Valve

Fault phenomenon: The valve cannot be fully closed, water leakage occurs at the sealing position.

Reasons: Impurities stuck between gate and valve seat; rubber seal aging or damaged; stem thread stuck causing incomplete closing.

Solution: Dismantle and clean internal dirt and sediment; replace aging EPDM rubber seal; lubricate stem thread and debug opening and closing stroke.

Fault phenomenon: Handwheel is hard to rotate, opening and closing is stuck and not smooth.

Reasons: Stem thread lack of lubrication; internal rust or foreign matter jamming; installation misalignment causing force deviation.

Solution: Add high-quality lubricating grease to stem thread; clean rust and dirt inside the valve; readjust pipeline flange alignment to avoid forced installation

Fault phenomenon: Water leakage at flange connection surface.

Reasons: Gasket aging, deformation or uneven placement; flange bolt loose or tightened unevenly; flange surface scratch and deformation.

Solution: Replace the new sealing gasket; tighten flange bolts diagonally and evenly; repair or replace damaged flange face.

Fault phenomenon: Water seepage from the stem packing position.

Reasons: Packing aging, loose or insufficient filling; stem surface rust and scratch causing seal failure.

Solution: Add or replace new packing; polish the stem surface and apply anti-rust lubricant; reassemble and compress packing properly.

Fault phenomenon: The valve can not open to the full flow position, flow rate is small.

Reasons: Internal parts corrosion and jamming; improper stroke limit adjustment; pipeline foreign matter blocking the flow passage.

Solution: Disassemble for cleaning and rust removal; readjust opening limit position; clear pipeline internal blockage.