• Trunnion Mounted Ball Structure: The ball is supported and fixed by upper and lower bearings, delivering stable operating torque unaffected by medium pressure fluctuations, making it suitable for high pressure differential and large bore applications.

• Spring Preloaded Seat: Disc springs or coil springs are installed behind the seats for preloading, ensuring initial sealing at low pressure while medium pressure enhances sealing performance at high pressure.

• Optional Double Piston Effect (DPE) Seat: Body cavity pressure acts on both upstream and downstream seats simultaneously, achieving reliable bidirectional sealing and fulfilling the DBB (Double Block & Bleed) function.

• Full Bore / Reduced Bore Optional: Full bore design meets pigging requirements, while reduced bore design lowers costs to adapt to various operating conditions.

• Flanged / Buttweld End Connections: RF (Raised Face) or RTJ (Ring Type Joint) flanges, as well as BW (Buttweld) ends, are available to suit different installation requirements.

• Fire-Safe Design: Complies with API 6FA / API 607 standards. Metal-to-metal sealing remains effective after soft seals are damaged by fire.

• Anti-Static Device: Anti-static springs are installed between the ball, stem and body to ensure effective discharge of static electricity.

• Blowout-Proof Stem Design: One-piece forged T-head stem structure prevents stem ejection caused by internal pressure.

• Emergency Sealant Injection: Sealant injection valves are provided at the seat and stem areas, allowing sealant injection to restore sealing in emergency situations.

• Seat Self-Relief Function: In the event of overpressure in the body cavity, the seat automatically disengages from the ball to relieve pressure to the low-pressure side, preventing overpressure damage to the valve body.

• Low-Torque Bearings: Upper and lower bearings adopt Devlon, PEEK or metallic bushings to reduce friction and enable smooth operation.

J-VALVES trunnion mounted ball valves standard seat ringsare soft-seated by the use of athermoplastic or elastomeric or Meta

Seats-Tungsten /Chrome carbide /ENP

Single Piston (SPE) , Double Piston effect (DPE) and Combination (SPE x DPE) seats are available.

Seat Princlple

Two independent seat rings grant the sealing, barrieragainst the line pressure actingon the upstream and downstreamsides of the valve which allows the valve tobe bidirectional.

A set ofcoil springs acting, between the upstream side ofeach seatring,andthe body,generate an uniform thrust on theseat which push the same against the ball and grant the sealingfeature with no orverylow pressureinthe line,when the line pressure increasethe thrust actingon theseat increases proportionally and the sealing leatureis granted throughout the fullpressure range.

The J-VALVES SPE trunnion mounted ball valves are available with Double

Block & Bleed in dependent oftheseat type.

Valve seating variations

Single Piston Effect

Single piston effect (SPE) is the stand ard feature for theseat rings of the J-VALVES SPE trunnion mounted ball valves.

On a SPE seat ring:

The pressure ac tingon the upstream side ofthe seat ringgenerates aforce which push theseattowards the ball.The pressure actingon the downstream side ofthe seatring generates a force which pull theseatring away fromthe ball.

Anyoverpressure which may be generated by the thermal expansion of the fluid trapped in thebodycavity with the ballin fully closed position, will beautomatically dischargedinthe line on the lower pressure side.

Double Piston Effect

Double piston effect(DPE) is a stand ard feature fortheseat rings ofthe J-VALVES trunnion mounted ball valves & recommended forwelded body valves. Ona DPE seat ring, both the pressure acting on the upstream sideof theseatring andthe pressure acting on thedownstreamside of the  seatring, generatea forcewhich push the seattowards the ball.

With th is type ofseat ring,the eventual over press ure whichmay be generated by the thermal expansion ofthe fluidtrappedinthebodyeavitywith theball in fullyclosed position,can be discharged by the use of:

An external safetyrelief device.

The Double Piston Effect grants a double sealingfeature,iftheupstreamseat ringisdamaged, thedown stream seatgrant the sealingfeature of the valve.