• Integral Forged Steel & Fully Welded Structure:The valve body is integrally fabricated by welding forged pipe sections and forged end parts, without body flanges or bolted connections. This completely eliminates external leakage risks of the valve, and the maintenance-free design delivers a service life of more than 50 years.

• Transition Sleeves Design:Forged transition sleeves are provided at both ends of the valve, enabling flexible transition connections to pipelines of different materials (such as X70/X80 line pipe steel), different wall thicknesses or different standards. It avoids on-site dissimilar steel welding difficulties, and reduces installation stress and thermal cycling fatigue risks.

• Fixed Ball / Trunnion Supported Design:The ball is precisely supported and fixed by upper and lower trunnions, achieving sealing independent of medium pressure. The operating torque is low and constant, ensuring flexible opening and closing even under high-pressure and large-bore conditions.

• Double Piston Effect (DPE) Seats:Bi-directional sealing design. In case of abnormal pressure buildup in the valve cavity, the seats will automatically tighten against the ball to prevent overpressure, and support DBB (Double Block & Bleed) function.

• Full Bore Design:The flow bore diameter is fully consistent with the inner diameter of the pipeline, resulting in nearly zero pressure drop. It allows unobstructed passage of pigs and intelligent inspection gauges, reducing pipeline maintenance costs.

• Suitable for Buried or Subsea Installation:The fully welded structure has no external leakage points, allowing direct buried or subsea installation without valve pits or waterproof sealing. The transition sleeves accommodate soil settlement and pipeline displacement.

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.