Wet steam and particles result in erosion on trim parts. If erosion affects sealing surfaces, this might result in leakage and overheating of downstream piping. This is especially common after supercritical pressure drops, where particles and steam have very high velocity. It is also more common when the valve is operating at a small opening degree. The quick change seat trim design reduces this problem by moving the super critical pressure drop from the seat area and bonnet cage. The critical pressure drop is taken over the plugs cage. A seat packing ring is placed under the seat to stop leakage.
The plug and seat also have stellite 6 hard facing as standard, further improving the sealing surfaces resistant to erosion. The plugs cage decreases the capacity of the valve, so it might be necessary to move to a larger seat size. The seat is not welded to the valve body, and thus does not need to be cut out. Seat removal and trim compression tools are included for quick and easy seat replacement.
- Quicker and easier seat exchange
- Reduced MTTR and longer service lifetime
- Reduced downtime and maintenance cost
- Reduced damage to valve seat