News Detail

After the use of gate valves, the following problems often occur due to the effects of medium temperature, pressure, corrosion, and relative movement of various contact parts.

(1) Leakage: There are two types, namely external leakage and internal leakage. Leakage to the outside of the valve is called leakage, which is commonly found at the packing box and flange connection.

The reason for the leakage of the packing box: the variety or quality of the packing does not meet the requirements; Aging of packing or wear of valve stem; Loose packing gland; Scratches on the surface of the valve stem.

The reason for the leakage at the flange connection: the gasket material or size does not meet the requirements; Poor processing quality of flange sealing surface; Improper tightening of connecting bolts; The pipeline configuration is unreasonable, resulting in excessive additional load at the connection.

The reason for internal leakage of the valve: The leakage caused by the valve not closing tightly is internal leakage, which is caused by damage to the valve sealing surface or inadequate sealing at the root of the sealing ring.

(1) Corrosion often occurs on the sealing surfaces of valve bodies, valve covers, valve stems, and flanges. Corrosion is mainly caused by the action of the medium, as well as the release of ions from fillers and gaskets.

(2) Scratches: Local surface roughness or peeling phenomenon that occurs when the gate and valve seat move relative to each other under certain contact pressure conditions.