2017年12月20日 · For standard API6D ball valves, both seats are self relieving. However, on request valves can be ordered with just upstream or just downstream seat as self relieving. Also “double piston effect” (DPE) seats can be specified. DPE seated valves must have an external relief safety valve fitted to the body which vents to atmosphere.

2019年12月16日 · Ball valve with DPE (Double Piston Effect) seals both at upstream or/and at downstream. When ball valves with DPE seats needs to achieve cavity over-pressure automatically, a extra pressure relief device need to be installed. Ball valves with SPE ( Single Piston Effect) seals only at upstream.

A double piston seat is recommended to be fitted to one side only ("downstream" seat) in liquid or condensing service and high pressure gas service. In this case the valve should be marked as required by ISO 14313 to indicate the directionality.

Double Piston Effect Ball Valves. API 6D definition: "Double Piston Effect Ball valve is a single valve with two seating surfaces, each of which, in the closed position, provides a seal against pressure from a single source, with a means of venting/bleeding the cavity …

There are two options: DPE Seat x Self Relieving Seat (DIB-2) or Double Piston Seat x Double Piston Seat (DIB-1). This design provides assurity of isolation in situations where servicing of other equipment is required up or and down stream. An external cavity relief mechanism must be fitted to DIB-1 valves.

2023年5月7日 · The ball of the trunnion ball valve is fixed while the seat is floating. The seat is divided into two types with single piston effect which has self-relieving action, abbreviated as SPE, and double piston effect, abbreviated as DPE. The principle of the single-piston valve seat is a one-way piston effect.

Double Piston Effect Ball Valve (DPE seat ball valves), A double piston effect seat, is a seat design, where the location of the seals on the back side of the seat are located in such a way that the seat can use pressure from either the pipeline or the valve cavity as a source of pressure to provide a piston force.

2024年8月6日 · Double Piston Effect Ball Valve (DPE seat ball valves), A double piston effect seat, is a seat design, where the location of the seals on the back side of the seat are located in such a way that the seat can use pressure from either the pipeline or the valve cavity as a source of pressure to provide a piston force.

A Double Isolation & Bleed (Double Piston Effect seat) valve is a valve with two seating surfaces each of which provide sealing in both directions in the closed position, with a means of a cavity vent or relief valve between the seating surfaces: seats are designed to seal with pressure from body cavity. Pressure test is performed without the ...

2006年8月1日 · Most double-piston effect valves will relieve cavity pressure at a certain level. They are not all non-self-relieving. For instance: When the valve is closed, the downstream pressure drops to 10 bar.