36
To meter body
(High pressure chamber)
To meter body
(Low pressure chamber)
Pressure range
for upstream-side
diaphragm
Pressure range for
downstream-side
diaphragm
Static pressure
distribution curve
2.5D
8.0D
6S
To transmitter
(High pressure chamber)
To transmitter
(Low pressure chamber)
Pressure tapping range
for upstream-side diaphragm
Pressure tapping range
for downstream-side diaphragm
Static pressure
distribution curve
Pipe diameter : 3 in. or over
Differential pressure : 1000mH
2
O or over
DIameter ratio : 0.30 to 0.70
Venturi tube throat diameter : 3 in. or larger
Differential pressure : 10 kPa {1000 mmH
2
O} or higher
DIameter ratio : 0.70
For flow measurement with orifice plate
For flow measurement with Venturi tube
Fig. 5-13. Pressure tapping for model 71 and 72 for flow measurement
(1) Fix the flanges of the meter body to those of the process side by using gaskets and bolts.
Be sure to uniformly and securely tighten the bolts in order to prevent leakage.
Install the capillary tubes in such manner that they are less subjected to large temperature
change. Secure them so that they do not move.
(2) Regarding the flange of the low pressure side when in level measurement of an open tank,
make sure to secure it in a position where it will be subjected to minimal temperature
change and mechanical vibration. Position the LP side flange at a height lower than that of
the minimum liquid level.
Regarding the seal diaphragm, protect it so that it will not damaged and pay attention so
that no drain will be entrapped on it and no dust will accumulate on it.
