• WCB Cast Carbon Steel Body:Constructed from ASTM A216 WCB cast steel subjected to austenitizing heat treatment, it features excellent mechanical strength, pressure-bearing capacity and castability. It is suitable for manufacturing large-bore complex-shaped valve bodies such as 12-inch ones, with costs reduced by 20%–30% compared with forging processes.

• Reduced Bore Design (12×10 Inch):The nominal valve size is 12 inches with a 10-inch bore diameter. This reduced bore design cuts valve weight by 25%–35%, operating torque by 20%–30% and manufacturing costs, while satisfying flow requirements for most large-bore process pipelines and improving economic efficiency.

• Two-Piece Body Structure:The valve body consists of a main body and a side body connected by bolts. The structure is simple and compact with good castability, facilitating large-bore production and on-site maintenance and disassembly.

• Trunnion-Mounted Ball:The ball is secured in the body bearings by upper and lower trunnions, maintaining precise positioning under 300LB medium-to-high pressure differential conditions. It avoids ball deflection and uneven wear of sealing faces seen in floating ball valves, ensuring long-term reliable sealing for large-bore valves.

• Dual-Seat Bi-Directional Sealing:Independent upstream and downstream seats deliver bi-directional sealing with no installation orientation restrictions. Soft or metal seats are available to suit various media and temperature conditions.

• Flanged End Connections:RF (Raised Face) or RTJ (Ring-Type Joint) flanged connections conforming to ASME B16.5 are adopted, enabling easy integration with existing large-bore piping systems and online maintenance.

• Fire-Safe Design:Compliant with API 607/ISO 10496 standards. In the event of fire damage to soft seats, metal seats come into contact with the ball to form a metal seal, preventing media leakage during fire incidents.

12x10 300LB WCB 2piece Trunnion Mounted 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.