Logic for Damper Closing

Make it 6 minutes and use a 30 minute cam timer.

do u mean a timer card

Look cam timer up!

I give up!

You can set up a simple PLC circuit which will energise/de-energise a solenoid to the supply valves (or pilot operated valves). Alternatively, it can all be done with pneumatics using a small capacitor bottle with a variable orifice. Depending on how you want to do it, you could sequence the pneumatics so that the second one opened after the first one closed etc. Depending on your time frame, this could be a good project for some local students or a graduate traineee, provided you get some bright, pro-active people on it. Otherwise talk to a local pneumatic equipment supplier who should be able to prepare a circuit for you and supply the necessary volume bottles, valves etc.