A-3
Model 752 and 752A Differential Pressure Transmitters
Appendix A
Gas Flow, DPU Below Run
The following steps are recommended only for applications that require the
DPU to be mounted below the run. Drip pots are required when wet gas is
present.
1.
Open the bypass valve(s) and close the vent valve.
2.
Open both shutoff valves and one block valve to pressurize DPU, then
close the block valve.
3. Close one bypass valve and check the system for leaks. If output travels
upscale, check for low-pressure piping leaks. If output travels downscale,
check for high-pressure piping leaks.
4. Repair piping if necessary and repeat steps 1 through 3 until output
remains stable at zero.
5. Close both shutoff valves and open the bypass valve(s).
6.
Open both block valves and slowly open both shutoff valves.
7. Close the bypass valves, and if two bypass valves are used, open the vent
valve.
8. If drip pots are used, open the drip valves and blow out accumulated
liquid.
BLOCK
VALVES
PRIMARY
DEVICE
STATIC PRESSURE
CONNECTION
(USE ONLY ONE)
BYPASS
VALVES
VENT
VALVE
SHUT-OFF
VALVES
DPU
DRIP POTS
Figure A.2—Gas Flow, DPU Below Run
