• A105 Carbon Steel Forging 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. It is suitable for high-pressure and alternating load conditions. The normalized version A105N is optional to improve low-temperature toughness.

• Three-Piece (3PC) Structure:The valve body consists of the left body, right body and intermediate main body, fastened by bolts. It facilitates online maintenance, trim replacement and seat inspection without removing the valve from the pipeline, greatly reducing system downtime, maintenance costs and production losses.

• Trunnion Mounted Ball Design:The ball is supported and fixed by upper and lower trunnions. Initial sealing is achieved by seat spring preloading, with medium pressure further enhancing the sealing effect. Operating torque is significantly lower than that of floating ball designs, preventing seal failure caused by ball displacement under large pressure differentials in high-pressure service. It ensures stable and controllable opening and closing, while reducing the size and cost of heavy-duty actuators.

• High-Pressure Flanged Connection:RF (Raised Face) or RTJ (Ring Type Joint) flanged connections are adopted in accordance with ASME B16.5. Pressure classes from Class 150 to Class 2500 ensure reliable sealing under extreme high-pressure conditions.

• Soft Seal:PTFE, RPTFE, PPL, suitable for normal-temperature applications with strict sealing requirements.

• Metal Hard Seal:Hardfaced with Stellite alloy or nickel-based alloy, suitable for high-temperature, high-pressure and solid particle-laden media.

• Fire-Safe Design:Compliant with API 607 / API 6FA standards. Metal seals or graphite packing maintain sealing performance in case of fire to prevent catastrophic leakage.

A105 Three Piece High-pressure Flange 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.