Pilot Seat Leaks

Pilot seat leakage has affected many valve types and can result from many factors including corrosion bonding, thermal distortions, insufficient or disrupted contact pressure, and pressure fluctuations. Steam cutting and oxidation on a pilot disc are shown below (Figure 1).

a) Oxidation on the nose of a pilot disc

b) Corrosion and steam cutting on a pilot disc

Figure 1: Corrosion and Steam Cuts on a Pilot Disc