DIB Ball Valve
Key Specifications / Features
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: 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.
DIB 2: 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.
If fluid trapping is possible, the valve shall be provided with automatic cavity pressure relief, unless otherwise agreed.
Valve cavity relief pressure when added to the valve pressure rating shall not exceed 133% of the pressure rating of the valve at its maximum specified design temperature.