Trunnion Mounted Ball Valves

A large trunnion design ensures central positioning under the highest working pressure. Independent floating spring loaded seats provide a tight seal even at low differential pressures. Service and maintenance is simplified with a bolted body design incorporating double o-rings or a combination of o-rings and gaskets, suitable for buried or above ground installation.


  • Three-piece body design
  • Double block and bleed
  • Self relieving seat
  • Double piston seat
  • Trunnion supported design reduces operating torque
  • Antistatic device for grounding of the ball, stem and body
  • O-rings plus firesafe stem packing prevent leakage
  • Corrosion resistant low friction bearings
  • Inconel® seat springs provide upstream and downstream sealing
  • Stainless steel sealant injection fittings for emergency stem or seal sealing
  • Direct mount topworks pad for actuator or gear operator
  • 6" & larger valves are equipped with lifting lugs
  • Locking device (lock not included)
  • Anti-blowout trunnion stem design


1 - Anti-Blowout Stem Design

Stem seal integrity is achieved by the use of three o-rings (or two o-rings and a graphite gasket). Upper o-ring (or graphite gasket) can be replaced with the valve in line and under pressure.

2 - Lubricant / Emergency Seat Seal

Special sealants may be injected through fittings that are located on the adapter flanges to restore sealing integrity if seat sealing surface is damaged. A second internal check valve provides backup to the fitting.

3 - Emergency Sealant Injection System

The sealant injection system located on the bonnet can be utilized in case of emergencies, o-ring damage, or if stem leakage occurs.

4 - Double Sealed Envelope Connections

Double o-rings or a combination of an o-ring and firesafe gasket on body/adapter connections to ensure positive sealing. This makes the P3/M3 suitable for above or below ground service.

5 - Heavy Duty Bearings

6" - 12" Class 900, 1500 & 2500
14" - 24" Class 150, 300 & 600
Trunnions are supported by heavy duty teflon® coated steel bearings. Thrust load on the ball is supported by large trunnions mounted within captured trunnion blocks, resulting in low operating torque and seat wear.

6 - Antistatic Device

A spring between the trunnion and the ball or between the stem and the gland plate permits electrical continuity between all valve components.