15
Model 753A Gage Pressure Transmitter
Section 3
specific to your piping configuration.
3.
Open the block valve if applicable (recommended for liquid service, but
not for gas).
IMPORTANT: For gas service, it is recommended that a zero check be performed with
the block valve closed. If the gas flow is pulsating, there may be a stand
-
ing wave effect in the process line which can displace the indicator and
appear as a zero error.
4. Apply electrical power to the Model 753A transmitter.
5.
Check the transmitter calibration across all checkpoints, using the in
-
structions provided in
Calibration, page 16
. If re-adjustment of the zero
and/or span is necessary, perform all 12 steps described in the
Calibration
Procedure, page 18
.
6.
Check the manifold and piping for leaks as follows:
a.
Open the shutoff valve to pressurize the instrument.
b.
Close the shutoff valve.
c.
Check for a change (increase or decrease) in the transmitter output
that could indicate leakage.
IMPORTANT: Be careful not to subject the gage pressure transducer to unnecessary
shock or overrange pressure during operations.
Shutdown Procedure
To shut down operations, perform the following steps.
1. Remove electrical power from the Model 753A transmitter loop.
2.
Close the shut-off valve.
3.
Close the main block valve at the process connections.
4.
Open the vent/drain valve to remove all pressure from the unit.
