• Stainless Steel Valve Body: Forged or cast from ASTM A182 F304/F316/F316L, A351 CF8/CF8M, F51/F53 duplex stainless steel, or super austenitic stainless steel, featuring excellent corrosion resistance to meet full working condition requirements from general corrosion to severe corrosion, and from low temperature to high temperature.

• Trunnion-Mounted Ball Structure: The ball is fixed by upper and lower trunnion shafts and does not float with medium pressure. Seating is achieved via spring-loaded seats, which significantly reduces operating torque. It is suitable for high-pressure and large-bore applications and eliminates the jamming issue of floating balls under high pressure.

• High-Pressure Design Capability: Design pressure up to Class 2500 (PN420) or higher to satisfy ultra-high-pressure working conditions; forged valve bodies or thick-wall castings ensure pressure-bearing safety.

• Double-Seat Bi-Directional Sealing: Upstream and downstream seats are independently spring-loaded to realize bi-directional sealing with no installation direction restriction. Single Piston Effect (SPE) or Double Piston Effect (DPE) seat designs are optional to adapt to different pressure relief requirements.

• Full Bore or Reduced Bore Design: Full bore design features near-zero flow resistance and allows pig passage; reduced bore design lowers costs and is suitable for general shut-off applications.

• Precision-Machined Ball and Bearings: Ball surface roughness Ra ≤ 0.4μm. Upper and lower bearings adopt SS316+PTFE or metal bushings with low friction coefficient, ensuring jamming-free long-term operation.

• Self-Relief and Emergency Sealing: Seat design supports cavity self-relief (SPE) or Double Block & Bleed (DBB) function. Emergency sealant injection is provided between the stem and valve body to restore sealing in case of fire or seal failure.

• Anti-Static and Fire-Safe Design: Conductive connections between the stem, ball and valve body ensure static electricity dissipation. Certified to API 607/ISO 10497 fire-safe standards, maintaining sealing integrity after fire exposure.

• Live-Loaded Packing System: PTFE or flexible graphite packing preloaded by disc springs automatically compensates for relaxation caused by temperature cycling and pressure pulsations, guaranteeing reliable long-term sealing.

• Extended Bonnet Neck and Low-Temperature Design: Extended bonnet necks and flexible graphite packing are equipped for low-temperature services to protect actuators from cryogenic effects. Cryogenic versions are suitable for -196℃ LNG media.

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.