Sealing face: ANSI B16.5 Raised Face (RF) or Ring Type Joint (RTJ), EN 1092 Form BFlushing rings are used with flanged chemical seal systems for flushing or venting the space immediately in front of the diaphragm. They are simply mounted between the flanged process connection and the diaphragm seal. The two flushing ports allow washing out of particles accumulated in front of the membrane and the pressure space can be vented or drained according to requirement.