Cameron Barton 752 - Shutdown Procedure

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Section 3 Model 752 and 752A Differential Pressure Transmitters
monitored). Follow the guidelines in Appendix A that are specic to your
piping conguration.
3. Open the block valves if applicable (recommended for liquid service, but
not for gas).
NOTE: For gas service, it is recommended that a zero check be performed with
both block valves closed. If the gas ow is pulsating, there may be a
standing wave effect in the process line which can displace the indicator
and appear as a zero error.
4. Apply electrical power to the transmitter loop.
5. Check the transmitter calibration across all checkpoints, using the
instructions provided in Calibration, page 19. If re-adjustment of the zero
and/or span is necessary, perform all 12 steps described in the Calibration
Procedure, page 21.
6. Check the manifold and piping for leaks as follows:
a. Open the bypass valve(s), then open one shutoff valve to pressurize
the instrument.
b. Close the shutoff valve and the bypass valve.
c. Any leakage will be indicated by a change (increase or decrease) in
the transmitter output.
NOTE: Be careful not to subject the DPU to unnecessary shock or overrange
pressure during operations.
Shutdown Procedure
To shut down operations, perform the following steps. See the installation
diagrams in Appendix A, page A-1, for typical valve locations.
1. Remove electrical power from the transmitter loop.
2. Close the transmitter shut-off valves.
3. Close the main block valves at the process connections.
4. Open the transmitter drain valves and remove all pressure from the unit.