Patent ID: 6035724
Filing Date: 2000-03-14
Classification: G01L

Abstract:
A method for accomplishing multi-valve function mode selection between a pressurized process having high and low differential pressure signals and a differential pressure transmitter having high and low pressure signal passages, comprising:(a) providing a rotary spool manifold connected to the pressurized process and the differential pressure transmitter having a manifold body defining a pair of signal passages in communication with said differential pressure signals of said pressurized process and a spool element being rotatable within said manifold body and having transverse signal passages therethrough and being located for registry with said pair of signal passages of said manifold body, said spool element having an equalizing passage disposed for selective communication with said pair of signal passages and being sealed with respect to said instrument body by a plurality of circumferential seal means located for isolating pressure signals of said pair of signal passages from one another, said spool element having a mode seal means establishing sealing with the outer periphery of said spool element and establishing sealing with said manifold body;(b) rotatably positioning said spool element at a ""RUN"" mode where said transverse signal passages of said spool element are in aligned registry with said aligned signal passages of said manifold body and enabling differential pressure of the pressurized process to be transmitted to the respective passages of the differential pressure transmitter through said signal passages of said manifold body and said spool element;(c) rotating said spool element from said ""run"" position to a ""ZERO"" mode where said transverse signal passages of said spool element are out of pressure transmitting registry with said pair of signal passages of said manifold body and said mode seal means blocks signal pressure from the pressurized process and said equalizing passage is positioned in communication with said aligned signal passages to the differential pressure transmitter for equalizing pressure in both signal passages of the differential pressure transmitter; and(c) rotating said spool element from said ""ZERO"" mode to said ""RUN"" mode.