• CF8 Stainless Steel Cryogenic Material:The valve body is cast from ASTM A351 CF8 (304) stainless steel. Its austenitic microstructure maintains excellent toughness at low temperatures with no risk of cold brittleness transition, making it suitable for cryogenic service down to -196℃. CF8M (316) or CF3M (316L) versions are available for enhanced corrosion resistance.

• Oversized Bore Design:The 28" (DN700) oversized bore meets high-flow requirements in LNG terminals, liquefaction plants and similar applications. The full-bore design produces extremely low pressure drop, reducing pumping energy consumption.

• Trunnion Mounted Design:The 28" oversized ball is supported and fixed by upper and lower trunnions. Initial sealing is achieved by preloaded seat springs, with medium pressure assisting in enhancing sealing performance. Operating torque is significantly lower than that of floating ball designs, preventing excessive ball displacement caused by pressure differential in large-bore service. This ensures smooth and stable operation under cryogenic conditions, while reducing the required size and cost of heavy-duty actuators.

• Extended Stem:The stem is standardly lengthened to position the packing gland away from the low-temperature body, preventing packing from freezing and failing.

• Drip Plate:A drip plate is installed at the middle of the stem to prevent condensate from running down the stem into the packing area and cryogenic zone.

• Cold Insulation Compatibility:The bonnet is designed to accommodate the thickness of pipeline cold insulation, ensuring continuous coverage of the insulation layer.

• Top Protective Tube:Protects the extended stem and operating mechanism against ice formation and mechanical damage.

• Three-Piece Body Design:Compact structure for easy maintenance and replacement of internal parts. Three-piece construction is commonly used for large-bore cryogenic valves, enabling in-line maintenance and minimizing system downtime.

Cryogenic 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.