Using the 5-valve manifold
In normal operation the “isolate” valves are open while the "equalize" and "vent" valves are closed. This provides a differential pressure reading to the pressure gauge or transmitter.
To zero the instrument, first close both “vent” valves and the downstream "isolate" valve. Then open the "equalize" valve and adjust the zero setting on the instrument.
To remove the instrument, first close both "isolate" valves, then open the "equalize" valves to relieve pressure between the manifold and the instrumet.

Note: The body & trim parts on all 316/316L Valves & Manifolds comply to NACE MR-01-75 & NORSOK M-650 as standard.