Seat sealing
Soft seats are standard. Seat inserts of synthetic material such as Nylon.
PTFE, RTFE, or Peek are contained within a one-piece metal seat ring with no or very low line pressure.
Sealing between the seats and ball is achieved by seat spring with higher line pressure.
The line pressure, in conjunction with the spring load, forces the upstream seat ring against the ball,which results in tighter sealing.
Self Relieve Seat
This feature is designed to prevent excessive pressure build up within the valve by automatically,relieving pressure when body cavity pressure exceeds the spring load on the seats.
Double Piston Seat is also available as and option.
Self Ring Sealing
Two o-rings or one each of an o-ring and graphite ring are used for pressure classes 150 through 600.
One lip seal with an o-ring or graphite ring is used for the pressure class 900 up to 2500.
Sealant Injection Fitting
This feature in standard except in sizes 2”~4” for pressure class 150, 300 and 600
In case of seat ring damage, sealant injection provides a fast, reliable way to restore tight sealing.
This injection system can also be used for routine flushing of the seat ring area white in service.
Stem Seal & Sealant Injection
Two o-ring and graphite packing are used for pressure classes 150 through 600.
One each of lipseal and o-ring plus graphite packing are used for pressure classes 900 through 2500.
In case of damage to the o-ring lipseat, sealant injection stops leaking and restores tight sealing.
Double Block and Bleed
Trunnion ball valves provide a positive seal at both upstream and downstream independently Since pressure on each side of the ball is blocked from the body cavity, a pressure releasing device can be used by an operator to check the integrity of the upstream and downstream seats.