• A105N Normalized Carbon Steel Body:The valve body is made of ASTM A105N normalized carbon steel. The normalization process refines grains and relieves forging stresses, improving low-temperature impact toughness by more than 50% compared with A105. It features excellent weldability, suitable for -46℃ low-temperature and welded installation conditions.

• A5215 Alloy Steel Key Components:Key friction components such as the ball and stem are made of ASTM A5215 (or equivalent Cr‑Mo alloy steel). After quenching and tempering plus surface hardening, their wear resistance, corrosion resistance and anti‑galling performance are significantly enhanced, making them ideal for services containing solid particles, high-frequency operation and severe working conditions.

• 6-Inch Large Bore Design:DN150 nominal bore satisfies high-flow and high-pressure fluid delivery requirements. The full bore design allows smooth passage of pigs and intelligent inspection devices, while reduced bore is available for optimized cost efficiency.

• Double Block & Bleed (DBB) Function:A single valve achieves dual-seat double sealing with a relief port in the intermediate cavity, complying with API 6D Appendix H DBB requirements. Pipeline isolation and cavity testing can be realized without series-connected dual valves, simplifying system structure and reducing potential leakage points by over 50%.

• Trunnion-Mounted Ball:The ball is secured in the body bearings by upper and lower trunnions, maintaining precise positioning under 600LB high pressure differential conditions. It eliminates ball offset and eccentric wear of sealing surfaces common in floating ball valves, ensuring long-term reliable sealing.

• Optional Double Piston Effect Seat (DPE):DPE seat design is available to provide bi-directional double sealing, with cavity pressure supported by both upstream and downstream seats. It is suitable for high-pressure natural gas pipelines and critical isolation services where zero leakage is required.

• Optional Flanged / Welded Ends:Flanged connections in RF (Raised Face) or RTJ (Ring Type Joint) face finish, as well as butt weld (BW) ends are provided. Flanges conform to ASME B16.5, and RTJ ring grooves ensure reliable metal-to-metal sealing under high pressure.

6" 600LB A105N A5215 DBB Ball Valves 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.