• One-piece Forged Steel Body: Forged integrally from forged steels including ASTM A105, A350 LF2, A182 F304/F316/F51 with compact grain structure, free from casting defects such as blowholes and sand inclusions. Mechanical strength is improved by more than 30% compared with cast steel, delivering excellent fatigue resistance, impact resistance and high-pressure durability.

• API 6D Standard Design: Designed, manufactured and tested in strict accordance with API 6D "Pipeline Valves" standard, covering requirements for valve structure, materials, dimensions, testing, marking and documentation. It ensures interchangeability and reliability in global oil and gas pipeline systems and supports API 6D monogram certification.

• Flanged End Connection: Equipped with RF (Raised Face) or RTJ (Ring-Type Joint) flanges complying with ASME B16.5, facilitating integration with existing piping systems and online maintenance. The RTJ ring groove ensures reliable metal-to-metal sealing under high pressure.

• Trunnion-Mounted Ball: The ball is fixed in the body bearings by upper and lower trunnions, maintaining precise positioning under high differential pressure, temperature fluctuations and frequent operation. It prevents ball deflection and uneven wear of sealing surfaces commonly seen in floating ball valves, ensuring long-term reliable sealing.

• Full Bore / Reduced Bore Optional: Full bore design allows smooth passage of pigs and intelligent inspection gauges (PIGs), supporting online pipeline inspection. Reduced bore design optimizes cost efficiency, lowering weight and operating torque.

• Double Seat Bi-Directional Sealing: Independent upstream and downstream seats provide bi-directional sealing. Seats are available with piston effect (self-relief) or double piston effect (DPE) design to meet cavity pressure management requirements under different operating conditions.

API6D Flange Forged Steel Trunnion Mounted Ball Valve 3D Diagram

J-VALVESSPE can supply a range ofseat types and configurationsto meet specific process needs:

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

Seat Design	Single piston effect (SPE)	Double piston effect(DPE)-DIB 1	Combined DIB 2
Bi-directional sealing	Yes	Yes	Yes
Body-Cavity Self relieving	Yes	No	Yes
Double Barrier	No	Yes	Yes (preferred direction only)

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.