Dual Isolation and Bleed (DIB-2 Single Seat Unidirectional and Single Seat Bidirectional) Valves with two honeycomb seats, one of which is a self-ejecting seat and the other a double piston effect seat (i.e. single piston effect seat SPE + double piston effect seat DPE). (Valve upstream seat once the loss of sealing, the downstream seat will also cut off the medium, generally used for liquid media or condensing conditions)
- D1B-2 Valve Seat Structure Details
DIB-2 type valves have two sealing seats with a blocking function at one end and a sealing seat with an isolation function at the other end (usually the sealing seat with a blocking function is set at the upstream end of the valve).
- DIB-2 valve seat pressure test method
- the valve half open, the valve and valve cavity completely filled with test medium (fresh water).
- then close the valve, open the valve cavity discharge device (drain or vent), so that the test medium from the discharge port overflow.
- Pressurize one end of the valve to 1.1 times the rated pressure of the valve housing material at 38°C. 4.
- through the valve cavity of the discharge port to view the valve leakage, acceptance criteria for soft seal 0 leakage, hard seal leakage is not greater than IS05208 in the D level.
- drain the pressure, repeat steps 3 to 4, the other end of the valve valve inspection.
- drain the pressure, the valve isolation seat end of the valve emptying, blocking the seat end of the valve and the valve cavity is full of media, blocking the seat end of the valve and the valve cavity at the same time pressurized to the valve shell material at 38 ℃ of the rated pressure value of 1.1 times.
- observe the isolation valve seat end leakage, acceptance criteria for soft seal 0 leakage, hard seal leakage is not greater than ISO5208 in the D level.
