Alicat's PCD-Series dual-valve pressure controller incorporates a second proportional control valve at its outlet to vent excess pressure. The PCD maintains a stable pressure through the central process port to the closed volume under test. This valve opens only when needed, so almost no gas is wasted.
If the system pressure becomes too great, the outlet valve opens to return the pressure to the chosen setpoint. Because this process happens a thousand times every second, the amount of gas lost while maintaining a constant pressure in a closed volume is exceedingly little. In this way, choosing a PCD for applications in closed volumes will save you a lot of money.
Ordering a PCD
When Alicat builds a PCD, we have a number of valves to choose from for both the inlet valve and the outlet valve. Correct valve sizing for PCDs depends upon the following three parameters:
Once you have provided these three parameters, our engineers will select the valves that will allow the most efficient filling and evacuation of your process volume while maintaining excellent control stability.
For those who require high flow rates into or out of the process volume at low pressures, we may recommend our PCRD Series. This series uses the same Rolamite valve that we use in our larger mass flow controllers for larger flows.
Typical Applications where the PCD may be used include:
We can supply full case studies for these applications – please call us today on 01953 609930 and ask for details.
Alicat's range of PCD dual valve pressure controllers are available in four different versions