Dec 20, 2017 · API6D trunnion mounted ball valves with single piston effect seats (SPE) are designed to automatically release cavity over-pressure into the pipeline automatically using “self relieving seats”.

Dec 16, 2019 · 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.

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 …

May 7, 2023 · Seats with Single-Piston Effect and Double-Piston Effect. 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 …

Jan 4, 2008 · Double piston effect seats are pressure energized in both direction. They will not release valve body cavity overpressure, a pressure relief design shall be added then. However, double piston effect seats offer valve sealing redundancy.

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.

Double-piston effect valves achieve the function of a single seat, whether channel pressure or cavity pressure, the seat is moving towards the ball, to achieve double-sided sealing, as shown in the figure below.

Double Piston Effect Ball Valve (DPE Ball Valves), Double piston effect seats are pressure energized to be pushed against the ball in both direction. For Double Effect Ball Valve, each seat will be sealed against the ball independantly for the …

SPE (Single Piston Effect) seats are usually called self-relieving seats. Trunnion mounted ball valves with SPE seats are able to release over-pressure in cavity into pipeline automatically. A SPE seat has seals on the back side located in such a way that the piston force can only come from the pipeline direction.

misunderstood subject… trunnion ball valve seat designs. In short, here is the 30 thousand foot view: • Double Block and Bleed (DBB) – Also known as Self-Relieving (SR). In case of thermal expansion, this design will relieve downstream • DIB 1 – …