A-5
Model 752 and 752A Differential Pressure Transmitters
Appendix A
Steam Flow, DPU Below Run
For this application, condensing reservoirs and piping to orifice taps must be
level. Assure that the reservoir and steam lines are at the same level. Two-inch
pipe crosses may be used as seal pots.
1. Close the vent valves, if used, and open the bypass and shutoff valves.
2.
Remove the condensing reservoir side and fill plugs.
3. Pour water into both reservoirs until the piping and the DPU housings are
filled. Piping and housing chambers shall be free of bubbles. The pointer
should rest at zero (or output will be 4 mA or 10 mA as applicable) when
the instrument and piping are completely filled.
4.
Install the side and fill plugs in the reservoirs.
5. Close the shutoff valves and open the block valves.
6. Slowly open both shutoff valves simultaneously and check for leaks.
7. Close the bypass valve.
NOTE:
Assure that plugs are used on the DPU. Valves should never be used on
the DPU.
DPU
PLUGS
BLOCK
VALVES
CONDENSING
RESERVOIR
PRIMARY
DEVICE
SHUT-OFF
VALVES
VENT
VALVES
(OPTIONAL)
Figure A.4—Steam Flow, DPU Below Run