• Fully Welded Body Structure: The valve body is integrally welded by forged pipe sections and valve body forgings using fully automatic Submerged Arc Welding (SAW) or Gas Shielded Arc Welding (GTAW/GMAW). With no middle body flange or bolted connections, it completely eliminates external leakage paths. The design service life is 30–50 years, matching the service life of the pipeline.

• Underground Extended Type: The stem is extended above ground level, equipped with an underground operating pit or ground stand, enabling excavation‑free operation and maintenance of buried valves.

• Low-Temperature Extended Type: The stem is extended beyond the influence zone of low‑temperature medium, keeping the stuffing box temperature above 0°C to prevent stem icing and operational sticking.

• High-Temperature Insulated Type: The stem is extended and fitted with cooling fins, keeping the stuffing box away from the high-temperature valve body to protect the sealing packing and operating mechanism.

• Safe Isolated Type: The stem is extended to a safe area or control room, enabling remote safe operation in services involving hazardous, radioactive or toxic media.

• Trunnion-Mounted Ball: The ball is secured in the body bearings by upper and lower trunnions, maintaining precise positioning under high pressure differential and fluctuating temperature conditions, preventing eccentric wear of sealing surfaces and ensuring long‑term reliable sealing.

• Full Bore / Reduced Bore Optional: Full bore design allows smooth passage of pigs and intelligent inspection devices, while reduced bore design optimizes cost efficiency, providing flexible selection according to service requirements.

• Double-Seat Bi-Directional Sealing: Independent upstream and downstream seats deliver bi-directional sealing. Seats are available in piston effect (self-relieving) or double piston effect (DPE) designs to meet cavity pressure management requirements for different applications.

• Flanged / Welded Ends Optional: Flanged connections (RF/RTJ) conforming to ASME B16.5 and butt weld (BW) ends conforming to ASME B16.25/API 1104 are available.

• Fire-Safe Design: Compliant with API 607/ISO 10494. In case of fire damage to soft seats, metal seats come into contact with the ball to form a metal‑to‑metal seal, preventing medium leakage during fire hazards.

Fully Welded Ball Valve Extended Stem  3D Diagram

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.