What are the Common Problems of Valves?

In the pharmaceutical, chemical and power industries, valves are a common component and play a pivotal role in the national economy. The operation and maintenance of the valve is crucial to the production of the enterprise. This article mainly describes the common faults and the methods what you can adopt when facing these problems.

Valve Body Leakage

According to reports, valve body leakage occurs when the valve body has trachoma, cracks or the valve body is pulled during repair welding.

Tips: Polish the suspected cracks and etch them with 4% nitric acid solution. If there are cracks, they can be displayed; then repair the cracks.

Stem Bend

This type of failure is mainly caused by the damage of the valve stem and the matching female thread, the valve head breakage, and the valve stem bent. The reasons may be improper operation, excessive force on the switch, failure of the limit device, over-torque protection does not operate, too loose or too tight screw threads, too many operations, long service life, etc.

Tips: improve operation ability, do not use excessive force; check the limit device and the over-torque protection device; choose the appropriate material to meet the requirements.

Leakage of Bonnet Surface

The reason for the leakage of the bonnet joint surface may be that the bolts are not tight enough; the gasket does not meet the requirements or the gasket is damaged; the joint surface is defective.

Tips: Tighten the bolts or make the gap of the door cover flange consistent; replace the gasket; disassemble and repair the sealing surface.

Leak in Valve

The stainless steel valve leakage may occur due to: loose closing; damage to the joint surface; too large gap between the valve core and the valve stem; poor contact of the valve core and sag; poor sealing materials or stuck valve cores.

Tips: You should reopen or close the device; valve disintegration, re-grinding of valve core and valve seat sealing surface; adjust the gap between valve core and valve stem or replace disc; disassemble the valve and eliminate jamming.

The Spool is Disconnected from the Valve Stem

When the valve core is separated from the valve stem, it is easy to cause the switch to lose control. The reasons include improper repairs; the joint between the valve core and the valve stem is corroded; the excessive force applied to the switch causes the joint between the valve core and the stem to be damaged etc.

Tips: Pay attention to inspection; replace the door rod type to corrosion-resistant one; check and replace the damaged spare parts.

Filling Leak

The leakage of the filling may be caused by: the filling material is not correct; the padding gland is not tight or biased; the method of installing the filling is wrong; the surface of the valve stem is damaged.

Tips: Select the filling materials correctly; check and adjust the filling gland to prevent pressure deviation; install the filling in the correct way; repair or replace the valve.