• WCB Carbon Steel Material:The valve body is cast from ASTM A216 WCB carbon steel, featuring excellent mechanical properties, high yield strength, strong pressure-bearing capacity and high cost-effectiveness. It is suitable for medium‑ and high‑pressure large‑bore applications with non‑highly corrosive media.

• Two-Piece (2PC) Body Design:The valve body consists of a main body and an end cap. It features a compact structure and light weight. Compared with a three‑piece design, it eliminates one set of sealing surfaces, reducing potential leakage points and manufacturing costs, while facilitating maintenance and replacement of internal components. The 8" large‑bore version adopts a two‑piece structure for enhanced rigidity, adapting well to medium‑ and high‑pressure conditions.

• Trunnion Mounted Design:The 8" large‑diameter ball is supported and fixed by upper and lower trunnions. Initial sealing is achieved by preloaded seat springs, with medium pressure further enhancing the sealing effect. The operating torque is significantly lower than that of a floating ball design, preventing seal failure caused by ball displacement under high differential pressure in large‑bore medium‑ and high‑pressure service. It ensures smooth and controllable opening and closing, and reduces the required size and cost of heavy‑duty actuators.

• Full Bore: The bore diameter matches the pipeline inner diameter, resulting in extremely low pressure drop and allowing passage of pipeline pigs, meeting the requirements of pigging and inspection for long‑distance pipelines.

• Reduced Bore: Reduces weight and cost, and can be selected according to actual working conditions.

• Flanged Connection:RF (Raised Face) or RTJ (Ring Type Joint) flanged connections are adopted in accordance with ASME B16.5. The 300LB pressure class ensures reliable connection under medium‑ and high‑pressure conditions.

• Fire‑Safe Design:Complies with API 607 / API 6FA standards. In case of fire, graphite packing and metal sealing structures maintain sealing integrity to prevent medium leakage.

ANSI Two Piece Carbon Steel 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.