WIKA 732.15.160 - Manual (Page 8)

5. Valve manifold with working pressure gauge (optional)
Working
pressure gauge
NS 100
Slotted
screw
Pressure equalising
valve
Isolating valve
j
Isolating valve
i
Test connection
M20 x 1.5
11236396.01B
A
8
11265191.07 12/2012 GB/D/F/I
WIKA operating instructions differential pressure gauge models 712.15.160, 732.15.160
GB
5. Valve manifold with working pressure gauge (optional)
The compact optional flanged valve manifold for an NG 100 working pressure gauge allows
the central measurement of level and working pressure in a single device.
„ To isolate line pressures without inter-
rupting the process, enabling gauge
removal/examination and protecting the
gauge against overpressure of n-times
rated pressure which may occur during
plant pressure testing.
„ To protect the gauge against pressure
surges/pressure spikes, and thus against
unspecified operating conditions
„ For gauge shut-downs, if no measure-
ments are required for long operating
periods, i.e. if only occasional measure-
ments are necessary (to increase service
life of those differential and working pressu-
re gauges with a high frequency of pressure
fluctuations).
„ Recalibration of differential pressure
gauges (tank volume display)
a) Open pressure equalising valve
b) Close the plus and minus shut-off valves,
and then close the pressure equalising
valve again
c) Connect the pressure standard and test pump using the additional G ¼ female port in
the plus chamber of the measuring system
d) Remove the test connection screw from the minus side valve manifold
e) The plus side can then be pressurised
f) After adjustment:
- Close the air bleed screw
- Disconnect the pressure standard and test pump and close the connection
- Open the integrated pressure equalising valve
- Slowly open first the plus and then the minus shut-off valve
- Close the pressure equalising valve
„ Test connection M20 x 1.5 for checking the working pressure gauge
The pressure equalising valve allows a zero point control during operation (with open valve).
„ While the media is flowing from the higher pressure side to the other side, the differential
pressure at the pressure gauge drops to zero (the differential pressure display must be at
zero, i.e. within the zero tolerance range which shows that the gauge is working correctly).
„ A zero adjustment can be made using the standard integra-
ted, adjustable pointer (remove snap fit bezel incl. window and
sealing ring beforehand). Twisting the slotted screw on the
adjustable pointer you can adjust the zero point.
After completing the zero adjustment, the snap fit bezel,
incl. window and ‚o‘-ring seal, must be correctly re-fitted
and the pressure equalising valve must then be closed again.
„ Subsequently the zero point of versions with integrated
transmitter (see page 9) should be checked.