• Fully Forged Steel Integral Body:The valve body is integrally welded from forged steel pipe sections and forgings of materials including ASTM A105, LF2, F304, F316, F51 (2205 duplex stainless steel) or F53 (2507 super duplex stainless steel). It features a dense grain structure free of casting defects such as blowholes and sand inclusions, with mechanical strength increased by more than 30% and excellent fatigue and impact resistance.

• Fully Welded Zero-Leakage Structure:The valve body eliminates middle flanges and bolted connections. It is integrally welded by fully automatic Submerged Arc Welding (SAW) or Gas Shielded Arc Welding (GTAW/GMAW), with 100% Radiographic Testing (RT) and Ultrasonic Testing (UT). This completely eliminates external leakage paths, resulting in near-zero leakage probability and a design service life of 30–50 years.

• Trunnion-Mounted Ball:The ball is fixed in the body bearings via upper and lower trunnions, maintaining precise positioning under high pressure differentials, temperature fluctuations and alternating loads, preventing uneven wear of sealing surfaces and ensuring long-term reliable sealing.

• Optional Full Bore / Reduced Bore:Full bore design allows passage of pigs and intelligent inspection tools, supporting pipeline in-line inspection. Reduced bore design optimizes economy by lowering weight and operating torque.

• Dual-Seat Bi-Directional Sealing:Upstream and downstream seats provide independent sealing to achieve bi-directional shut-off. Seats are available in piston effect (self-relieving) or dual piston effect (DPE) designs to suit cavity pressure management requirements in different operating conditions.

• Optional Flanged / Welded Ends:Butt-welded (BW) ends are provided as standard, with optional flanged transition ends (RF/RTJ). Welded ends comply with ASME B16.25 / API 1104, and flanges comply with ASME B16.5.

Forged Steel Fully Welded 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.