Additional equipment
Bourdon tube, capsule, diaphragm,
spring diaphragm pressure gauges
33
9
Additional equipment
9.1
Shut-off unit
A shut-off unit between the pressure tap point and the pressure
gauge allows you to check the zero point of the pressure gauge or to
dismount the pressure gauge without interrupting the process. De-
pending on the application, you can use valves or cocks.
CAUTION
Injury due to escaping fluid
Arrange the vent opening into the atmosphere in such a way as
to prevent persons from being injured by escaping fluid.
Cocks have three settings:
•
Vent: The supply line is closed and the measuring device is
connected to atmospheric pressure. The zero point can be
checked.
•
Operation: The supply line is open and process pressure is ap-
plied to the measuring device.
•
Blow out: The supply line is open, the fluid is discharged into the
atmosphere. The measuring device is out of operation.
Valves (for example, as per DIN 16270/16271) usually feature a
bleed screw between the valve seat and the pressure gauge.
In certain applications (for example, steam boilers), the shut-off units
must have a test connection so that the pressure gauge can be
checked without having to be dismounted.
9.2
Pressure gauge holder
If the measuring line is not sufficiently stable to carry the pres-
sure gauge without transmitting vibrations or shocks, install a
pressure gauge holder.