• A105 Forged Steel Material:The valve body is integrally machined from ASTM A105 forged steel, featuring a dense grain structure free of casting defects, excellent mechanical properties and high pressure-bearing capacity, making it suitable for medium‑high pressure and alternating load applications.

• Fully Welded Structure:The valve body is connected to the pipeline by full butt weld (BW) without flange sealing faces or bolted joints, completely eliminating external leakage risks. It features a compact and lightweight design, reducing weight by approximately 30%–40% compared with flanged valves, thus saving installation space and support costs.

• Trunnion Mounted Ball Design:The 12" large‑bore ball is supported and fixed by upper and lower trunnions. Initial sealing is provided by spring‑loaded seats, with medium pressure further enhancing the sealing effect. It delivers low operating torque, prevents excessive ball displacement caused by pressure differential under large‑bore high‑pressure conditions, and ensures smooth opening and closing.

• Full Bore Design:The flow passage diameter matches the pipe inner diameter, resulting in extremely low pressure drop and allowing smooth passage of pipeline pigs to meet the requirements of pigging and inspection for long‑distance pipelines.

• Suitable for Direct Buried Installation:The fully welded structure has no external leakage points and can be directly buried without a valve chamber, or with greatly reduced chamber size. An extended stem and top protective tube are available for ground operation.

• Fire‑Safe Design:Compliant with API 6FA standard. Metal seals and graphite packing maintain sealing integrity in case of fire to prevent catastrophic leakage.

• Anti‑Static Device:Built‑in anti‑static spring and conductor ensure electrical continuity between the ball, stem and valve body, preventing static buildup and explosion hazards.

12" 300LB A105 Fully Welded Trunnion 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.