• Dual ball DBB configuration: Two independent ball and seat assemblies are arranged in series within a single valve body, providing true double block-and-bleed functionality. A bleed port is integrated in the intermediate cavity to meet the DBB requirements of API 6D Appendix H, enabling online seal integrity testing and safe pressure relief of the valve cavity.

• High-pressure design capability: Pressure classes from Class 600 to Class 2500 (PN100 to PN420) are available, suitable for long-distance transportation and storage systems of high-pressure natural gas, crude oil and chemical media.

• Full bore / reduced bore optional: Full bore design facilitates pigging and pipeline cleaning operations, while reduced bore design optimizes cost efficiency, allowing flexible selection according to service conditions.

• Trunnion-mounted dual balls: Both balls are secured by upper and lower trunnions, ensuring stable performance under high differential pressure conditions, preventing uneven wear of sealing surfaces and guaranteeing long-term zero-leakage performance.

• Independent seat sealing system: Each ball is equipped with independent upstream and downstream seats for bi-directional sealing and bi-directional pressure-rated installation. Seats are available with a dual soft seal + metal seal design, achieving zero leakage at ambient temperature and fire-safe backup.

• Flanged / welded ends optional: RF / RTJ flanged ends and butt-welded (BW) ends are provided. Flanges conform to ASME B16.5 and welded ends comply with ASME B16.25, adapting to various installation requirements.

• Fire-safe design: Compliant with API 607 / ISO 10497 standards. In case of fire damage to soft seals, metal seats contact the balls to form a metallic seal, preventing medium leakage and ensuring safety.

• Anti-static device: Anti-static springs are installed on both balls and stems, ensuring effective static discharge between all metallic components with resistance < 10Ω, preventing explosions caused by static accumulation.

• Blowout-proof stem design: Bottom-entry stem is designed with an anti-blowout shoulder. Even if the packing gland is accidentally removed, the stem remains retained by the valve body, ensuring operational safety.

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.