Cole Parmer 16 Series, Operating Manual

Page: 22 / 41

22
PCD Series Dual Valve Pressure Controller Operation
PCD Series Closed Volume Pressure Controllers
Cole-Parmer PCD Series Closed Volume Pressure Controllers incorporate a digital pressure gauge
with dual control valves and circuitry. The integrated PID loop measures the pressure, compares it with
the set-point, and adjusts either the Inlet or Exhaust valve accordingly in excess of two thousand times
per second.
It is most common to have a .050 inch diameter orifice in the inlet valve, and a .050 inch diameter
exhaust valve. The response time of the system will depend on the size of the volume being controlled
and the feed pressure. The controllers are intended for use with clean, non-corrosive gases only.
They are designed with a feed port, a process port, and an exhaust port. This allows the controllers
to raise and lower the pressure of a closed system within the operating range of the controller without
wasting gas under constant pressure conditions.
Plumbing
Connect your PCD into your process via the 1/8” NPT port on the front of the unit. This is the
“Process” port.
Connect a supply pressure greater than the full scale pressure control range of the device, not to
exceed 145 PSIG, to the inlet 1/8” NPT port on the left side device. This is the “Inlet” port.
The 1/8” NPT “Exhaust” port, located on the right side of the device can vent to atmosphere if the
application is suitable, or to a collection network if necessary.
The pressure at the exhaust port should be at atmospheric pressure or below to allow the controller to
be used over its full scale range.
If desired, there are two 8-32 mounting holes located on the bottom of the unit as shown in the dimensional
drawing on page 36.
Connect your PCD to power and output lines as detailed in the “Wiring” section in this manual.
Figure 19. PCD Plumbing Diagram