Differential pressure instrument support manifold having rotary mode

Abstract

A spool type differential pressure transmitter support and valving manifold having a manifold body defining a process face and a transmitter face and having a generally cylindrical internal surface defining an open ended spool chamber and having signal inlet and outlet passages intersecting the process and transmitter faces and being in communication with the spool chamber. The manifold body also defines a vent passage which is in communication with said spool chamber. A spool member is positioned for rotation to 'run', 'zero' and 'off' positions within the spool chamber, has ends extending from the open ends of the spool chamber and has a pair of transversely oriented body passages positioned for selective registry with the signal inlet and outlet passages at the 'run' position of the spool member. Circumferential seals each preferably comprising an O-ring and a back-up ring establish sealing between the spool member and the manifold body and serve to isolate the signal passages from one another and to prevent leakage of signal pressure at the open ends of the spool chamber. A plurality of mode seal elements are carried by the outer periphery of the spool member and provide for manifold mode selection to the 'run', 'zero' and 'off' positions responsive to rotational positioning of said spool member relative to said manifold body to permit calibration of the differential pressure transmitter with the pressurized process in operation.