• Fully Welded Body Structure: The valve body is automatically welded with forged steel pipe, featuring no external leakage points and forming an integrated structure with the pipeline. Its design service life exceeds 30 years with no on-site maintenance required.

• Gas-Hydraulic Actuator: Using pipeline natural gas or nitrogen as air supply, combined with a hydraulic cylinder drive system, it delivers high torque output and fast opening/closing action. It features automatic position holding or emergency shutoff upon air loss to ensure system safety.

• Full Bore Design: Adopts a full bore structure with minimal flow resistance, allowing pig passage and meeting pipeline pigging requirements.

• Trunnion Mounted Design: Trunnion mounted structure is adopted for large diameter and high-pressure service. The ball is supported by upper and lower stems with stable operating torque and reliable sealing performance.

• Self-Relieving Seat Design: The valve seat adopts self-relieving or double piston effect (DPE) structure to prevent abnormal pressure rise in the valve cavity and ensure safe operation.

• Double Block and Bleed (DBB): Compliant with API 6D requirements, it provides double block and bleed function for easy cavity inspection and maintenance.

• Emergency Shutdown (ESD) Function: The gas-hydraulic system is equipped with an ESD module, which can receive remote control signals or pipeline rupture detection signals to realize rapid automatic shutoff.

• Fire Safe Design: Compliant with API 607 / API 6FA standards, the valve maintains sealing performance under fire conditions to prevent medium leakage.

• Anti-Static Device: Built-in anti-static structure effectively prevents static accumulation and reduces fire and explosion risks.

• Blowout-Proof Stem Design: The stem adopts blowout-proof construction to guarantee operational safety.

• Optional Buried Installation Design: Extended stem and protection sleeve are optional for buried installation, facilitating ground operation and maintenance.

Gas-Liquid Operated Fully Welded 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.