DIB Ball Valve

DIB ball valve provides a seal against pressure from a single source, with a means of venting/bleeding the cavity between the sealing surfaces.

DIB ball valve definition in API 6D:

Single ball valve with two seating surfaces, with two sealing 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 between the sealing surfaces. This feature can be provided in one direction or in both directions

Two types of DIB ball valves:

DIB-1 Ball Valve: Double Piston Seat x Double Piston Seat

For the DIB Double Piston x Double Piston (DIB-1)configuration, over pressurization of cavity is external with a safety valve.

Upstream and downstream sealing; pressure energized; two seats are bidirectional sealing seats.

Advantage: Each seat can isolate the fluid from upstream and downstream, if one seat is damaged, the other seat still work to ensure the sealing performance.

                                                           DIB-1 Ball Valve

                                                      DIB-2 Ball Valve

DIB-2 Ball Valve: DPE Seat x Self Relieving Seat

For the DIB Self relieving x double piston (DIB-2) configuration, cavity over pressurization is internally controlled within the line.

Upstream and downstream sealing; pressure energized; one seat is bidirectional seat and one seat is unidirectional sealing seat.

For DIB-2 Ball Valve,  the fluid can be relieved from one seat to downstream side.

Advantage: Self-relieving seat, no need to assembly the safety valve for pressure relieving.

Both DIB-1 & DIB-2 are for trunnion mounted ball valve structure.