Control.com - Nerds in Control

I have a client that controls vacuum to their process with a standalone controller installed between a couple of vacuum pumps and the process. They would like to improve control by replacing the standalone with a PLC controlled modulating valve. The existing valve is a 1/4" (one quarter inch) on/off solenoid. Can anyone recommend a good, 1/4 - 1/2 inch, electrically actuated, modulating valve suitable for controlling vacuum around 25 mmHg absolute?

There are so many out there, pick up a vacuum controls catalog, go to the internet, contact MKS instruments....

if you want me to do the research for you, I need a PO.

MJH

If the PLC has a PID controller built in and the supporting analogue I/O then your valve will need the relevant actuator and positioner.

Whether you have electric or pneumatic actuator is down to site needs, but the electric up/down pulsed actuator fits a PLC digital output controller better.

You could approach any of the (few remaining!) valve manufacturers. ABB, Metso, Invensis are all reliable.

1/4 - 1/2 inch is a large range to consider: if the current 1/4inch is pulsing 'lumps' of volume, then I would expect the 1/2inch will be modulating too far down it's curve for optimum control.

Look at Samson. They are one of the large players in the control valve world. Get me process info (pressure, temp, flow etc) and I can size up what you need.

johrow@accontrols.com

John