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.

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(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.

Low Emission Stem Sealing

J-VALVES SPE tandard stem sealing arrang ement offers Low Emission using a tri ple barrier arrangement certified to the latest lS0 15848 standard.

Anti-Blowout ProofStem

Stem is retained by the cover, the gland plate can beremovedwithvaweinfullyclosed position with the bodycavityvented toatmosphere. The upper stem Oring can be replaced formaintenance with valve in service

Anti-Static Device

All J-VALVES SPE Trunnion Mounted Ball Valves,areequippedwith an anti- static devicetoassurethetotalelectricalconductancebetween all metalparts of the valves.

Fire Safe

All J-VALVES complete range of Side entry,Top Entryand Welded body ball valves are certifiedfire safe according to AP1607/1S0 10497 - API6 FA.

Valves Ends

Valves are available with:

Flanged Ends (RF Or RTJ) tO ASME B16.5 0r ASME B16.47 Welding Ends to ASME B16.25Hub EndsCustomerspecific

Bore

Valve canbe supplied with Fullor Reducedbore in accordance with tablel of API 6D,unless other wiserequired oradvised. Valveswith special Bore are available.

Face to Face/End to End

Dimensions are in accordance withAP| 6Dand ASME B16.10.Specialdimensions areavailable.

Painting

Standard external painting is Sky Blue Ral5015,and systemis suitable to protect thevalve external suraceduringtransportationandstorage.Othertypesofpaintingareavailableon request.

Valve Transition Pieces

Transition pieces (pups), can be supplied forWeldingEnds Valwes to facilitate the welding ofthe valve totheline for:

Material compatibility.

Exces sive difference in strengthsand thickness betweenvalve closures and line pipe (limit is 1.5 times).

Avoiding damages to the valve soft seals.Important note: When transition pieces are supplied bythe customers, itisimperative to verifyif the strengthofthe same, suitable to undergothe hydro- test ofthevalve without damages ordeformations(1.5 times thevalve maximum rated pressure)

Welded overlays,with Stainless Steel, Duplexand Inconel are available on request for:

All wetted parts

Body wetted parts

Seat ringshousing pocket

Stem sealingarea

Balls