• Integral Forged Valve Body:Machined from solid forgings including A105N, F304, F316, F11, F22, LF2, etc. Featuring dense metal structure without casting defects, excellent mechanical properties and significantly higher pressure-bearing capacity than castings. Suitable for high-pressure and alternating load conditions.

• Three-Piece (3PC) Structure:The valve body consists of 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 and maintenance costs.

• Trunnion Mounted Ball Design:The ball is supported and fixed by upper and lower trunnions. Initial sealing is achieved by seat spring preloading, and medium pressure further enhances the sealing effect. With low operating torque, it is suitable for high-pressure and large-size applications, avoiding seal failure caused by excessive ball displacement due to pressure differential, ensuring accurate and smooth actuation by pneumatic actuators.

• Double-Acting Type:Both opening and closing are driven by air supply, delivering high output torque, suitable for large-size and high-pressure differential conditions.

• Single-Acting Type (Spring Return):One direction is driven by air supply, the other by spring force. Automatically resets to a safe position upon air loss (Fail Open FO or Fail Close FC).

• Air Supply Pressure:0.4~0.7 MPa (4~7 bar), operable with standard industrial air supply.

• Switching Time:1~60 seconds (adjustable, depending on size, pressure class and actuator specification).

• Control Modes:Solenoid valve on-off control, positioner proportional regulation, intelligent valve controller.

• Optional Accessories:Solenoid valve, limit switch, positioner (4~20 mA), filter regulator, speed control valve, handwheel override, travel switch, valve position transmitter.

Pneumatic Three Piece Forged 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.