Alternate Flap Valve


Thread Starter


Hi friends,

We have small motorised Flap Valves in Air flow duct of Dust Collector. Since these are geared motors & movement of flap valves is only 90 degrees for open / close operations, gears in that particular area come in to action & gets damaged frequently. Can anybody suggest a robust & simple mode of operations for such Flap Valves without Geared motors? If further details are required, we can provide. Basic data: Duct size: 150 MM, Air Pressure 5 Kg/ CM sq., frequency of operation On/Off: 2 times in a minute.

Hi there,

If you only need on/off control twice a minute the simplest way is to remove the motor and connect a lever on the shaft of the flap valve. Use a small air piston to push this lever to open and close the flap valve. The same power used for the motor can be used to drive a double acting solenoid valve to supply air to the piston for open as well as for close. You can install a restrict or (small needle valve) after the solenoid to control how fast you want the air to get to the piston therefore controlling the speed of the open/close action of the flap valve.

If you need confirmation in the CCR that the valve is open or close you can install limit switches on the piston.

If you need a open or close action to take place during a emergency you need to use a spring in the piston for the action you require. Meaning if you want the valve to stay open during a power or air failure you need to get a piston that will be extended all the time and needs air to retract it or visa versa. Even with a spring piston it is still a good idea to use a double acting solenoid valve so stay with that regardless what type of piston you decide on.