• Austenitic Stainless Steel Forged Valve Body:The valve body is forged from ASTM A182 F316/F316L/F304/F321/F347 etc., offering excellent resistance to general corrosion, high-temperature creep and low-temperature brittleness, covering the full temperature range from cryogenic to ultra-high temperature.

• Metal-to-Metal Hard Sealing Technology:The ball and seat are precision lapped and matched with hard materials such as Stellite alloy, tungsten carbide (WC), nickel-based alloy (Inconel 718) or ceramic coating, achieving zero-leakage metal sealing. It withstands temperatures from -196℃ to +650℃, and resists erosion by solid particles and wear from high-velocity gas flow.

• Resilient Metal Seat Structure:Elastic graphite or metal spring energized rings are installed at the back of the seat to compensate for high-temperature thermal expansion, low-temperature contraction and wear clearance, ensuring stable sealing specific pressure across the full temperature range.

• Solid Forged Three-Piece Structure:The main body and both side end caps are fully machined from forgings with a dense grain structure and free of casting defects. The symmetrical three-piece design allows convenient in-line disassembly and maintenance without removing the entire valve from the pipeline.

• Trunnion-Mounted Ball Design:The ball is precisely supported by upper and lower trunnions, achieving sealing independent of medium pressure. Operating torque is low and consistent, completely eliminating ball deformation risks under high pressure and large size conditions.

• Dual-Seat Bi-Directional Sealing:Double Piston Effect (DPE) metal seats or Double Isolation and Bleed (DIB‑1/DIB‑2) structure are adopted to provide reliable bi-directional sealing and meet DBB (Double Block & Bleed) requirements.

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.