What Are three Common Valve Failures?

The seat, which provides the valving component a tight seal when closed, is a common source of failure. For example, in the Rubber Lined Pinless Butterfly Valve​, or the Soft Seat And Lever Operator grooved end butterfly valve, the soft seat (commonly EPDM, Nitrile, or PTFE) is subject to wear. It can be compromised by high temperatures, chemical attack, abrasive media, or just wear and tear with time. Cavitation​/high velocity flow can also wear out the seal surface. Seat failure results in an internal leak, and the valve will no longer stop fluid flow. In high-end applications, Coating DiscU Section Type Butterfly Valve​ utilizes special disc coat to increase disc wear and corrosion resistance protection, which directly against such failure mode. 

The stem attaches the disc to the actuator. "Here failure often means inoperable valve." In Stainless Steel Flange Butterfly Valves, the stem will be usually stainless to resist corrosion. But in less-expensive versions or in harsh environments, stems and bearings can rust, particularly if seals break down and moisture get inside. A PinleSs Butterfly Valve​ design removes the through-shaft pin for a potential wear and leak point, the longevity of which is further enhanced. Nonetheless, the stem may seize (be unable to be rotated) due to stem corrosion in general, or accumulation of deposits. To achieve this jammed state, regular maintenance and proper material selection for the stem and bearings is important.

Butterfly valves depend on an operator — whether that is a simple lever, gearbox, or automated system such as a Pneumatic Butterfly Valve. This system is notorious for failures. Many linkages especially from lever operated valves can be bent by over-torquing or disc can be damaged. 

Pneumatic Butterfly Valves, air supply failure, solenoid valve malfunction, diaphragm leak or spring return mechanism failure will cause valve STOP working. A even working valve body will fail if its actuator does. This is why it is so important to choose the right size actuator for the valve torque and the type of valve, whether it be Double Flanged Butterfly Valve​ for high pressure piping or Grooved End​ for faster installation.