What type actuator would be best to use with butterfly valves?

Question

Isn't spring loaded be better than double acting actuator ? And can water be used as a working fluid in pneumatic actuator ?

Answer 1

If you consider the butterfly valve as just open or closed, a spring return type might be better for loss of actuator supply pressure if you want it to open or close in this situation (fail safe). Spring loading needs more force to operate. There are pneumatic actuators with servo control (position) too.



An electrical actuator is always double acting as far as I know, and could be used to get an intermediate position (servo actuator) and potentially maintain a position with loss of power. A basic linear electric actuator has no position control except the limits. Probably easier to implement for a position control.



It seems possible for a pneumatic actuator to use water as the fluid if the materials are suitable, but water will be vented most likely, as the air operation just vents air to atmosphere when control pressure drops, maybe through a small hole. Cutting off the pressure supply (say with a solenoid valve) does not necessarily drop the operating pressure. Pressure has to be bled away, to a drain in the case of water pressure from a tap. You would need to experiment. Consider freezing too. Think about why such a system is not on the market (as far as I know), though they are possible. Hydraulic systems (with oil, and potentially water) have a recirculating fluid system driven by a pump.

Answer 2

What is your Size of BF valve ? .You can use Hydraulic Power Cylinder type with Counter Weight fitted Valve can be used. In case of Power failure valve can be closed by help of counter Weight. In this case single acting power cylinder is enough. In this A hydraulic Pump will be pressurising a Pressure Cylinder up to 200 Bar & switched off . In open command a DC Solenoids valve only operate & pass the pressure fluid to power cylinder & open the Valve. Same time Hydraulic pump will start & maintain the Pressure. If the Valve is so Big >1500mm double acting power Cylinder type can be fitted. Pl consult with Good supplier the will recommend you the right rated valve Actuator & choose according to your budget. In some case Motorised valve can be used If it is a control valve to maintain various pressure. In case of Huge size pump Various Limit switches are require for close, crack open 30 '' open & fully open.

Answer 3

Depend upon the size of the valve*(Dia of pipe) we need to design the actuator

Hydraulic oil is best than water..

For small vales spring loaded may be okey for larger size double acting ones will be better.