Accumulator sizing for control valve pneumatic actuator.
Accumulator sizing for control valve pneumatic actuator.
(OP)
Feedwater Miniflow Valve - valve is normally held closed against spring during plant operation. If feedwater flow is isolated, the miniflow valve must open in 5 secs.
Givens: Instrument Air at 80 psig
Control Valve with 5" stroke
Actuator: Double acting with spring Fail-to-open
Piston area ~200 sq. in.
Required Valve stroke time: 5 seconds
In order to meet the 5 sec. requirement it appears that air assist is needed. And, in order to supply this intermittent demand an accumulator is needed at the valve. This is about 50 scfm for 5 seconds. What size should the accumulator be? Or how to go about sizing?
Thanks
Required:
Givens: Instrument Air at 80 psig
Control Valve with 5" stroke
Actuator: Double acting with spring Fail-to-open
Piston area ~200 sq. in.
Required Valve stroke time: 5 seconds
In order to meet the 5 sec. requirement it appears that air assist is needed. And, in order to supply this intermittent demand an accumulator is needed at the valve. This is about 50 scfm for 5 seconds. What size should the accumulator be? Or how to go about sizing?
Thanks
Required:




