6
Mounting
All P Series Gauges and PC Series Controllers have mounting holes for convenient mounting to flat
panels. These meters are position insensitive and can be mounted in any orientation. The sizes and
dimensions for the mounting holes are shown on pages 32 to 36.
P Series Pressure Gauges may be connected into your system with the flow going in either direction
for ease of viewing the display. These units are shipped with a plug for dead end applications. This plug
should be removed for flow through applications.
PC Series Vacuum and Pressure Controllers are normally intended to control the process pressure
downstream of the controller. In order for this to occur the controller should be mounted so the flow
goes from left to right as you look at the front of the unit. This puts the measuring portion of the device
between the valve and the leakage point where you are attempting to control the pressure application.
Back-pressure controllers reverse this configuration (see Fig. 15, page 19).
Using P and PC Series Instruments with Fluids
All of these devices may by used with chemically compatible liquids providing a couple of things are
taken into account:
1. Water is about 50 times more viscous than air. This is important when sizing a pressure controller.
The PC Series which can be used to flow up to 20 SLPM of gas, will be limited to roughly 0.5
LPM of water-like fluid. The PCR will be limited to roughly 30 LPM of water-like fluid.
2. The factory PID tune is established using air flow. It may be necessary to adjust the PID tuning
parameters if you will be using a controller with liquids.
Special Configurations
P, PC, and PCR Series pressure devices are occasionally ordered with special configurations which
are covered here:
1. External Sense Port: Occasionally it is necessary or desirable to sense the pressure at some
point other than at the location of the pressure device. All P, PC, or PCR Series pressure devices
can be ordered with an additional NPT port which is connected directly with the pressure sensor
of the device. In these devices the flow path through the device is NOT connected to the pressure
sensor. See “PC3 Series Pressure Controllers” – page 20.
2. Differential Pressure: Occasionally it is necessary or desirable to monitor or control a differential
pressure. P, PC, and PCR Series pressure devices can be ordered as low differential pressure
devices (usually 1 to 5 PSID). These devices have two ports located on the front face of the unit
for connection to the points in the system where the differential pressure is to be measured. The
upstream port is for the higher pressure and the downstream port is for the lower pressure. In
these devices the flow path through the device is NOT connected to either leg of the differential
pressure sensor. See “Differential Pressure Gauges and Differential Pressure Controllers” –
page 21.