3" throgh 6" rubber seated butterfly valve popping out of seat
3" throgh 6" rubber seated butterfly valve popping out of seat
(OP)
I have several 3", 4" and 6" butterfly valves with double acting air to air actuators on them. The valve seat is a dovetail design. The actuators have no travel stops. When solenoid is energized to open the valve the valve disc suddenly pops out of the seat.
I have heard that a cartridge design seat may work better.
I do not think the seat is being attacked by any chemicals.
I think the actuators should also have closed travel stops to prevent the disc from going to far into the seat.
The media flowing through the valve is clean.
Does anyone have any experience with this problem? What was the cause and what was the cure?





RE: 3" throgh 6" rubber seated butterfly valve popping out of seat
Mike Halloran
Pembroke Pines, FL, USA
RE: 3" throgh 6" rubber seated butterfly valve popping out of seat
Offshore Engineering&Design
RE: 3" throgh 6" rubber seated butterfly valve popping out of seat
Advice given above from both MikeHalloran and chief is sound (provided your fluid is compatibel with sealings suggested).
You could also try to throttle the air out of the actuator to soften the opening movement. (You do not say anything about line and air pressure.)
If you still, after 'redisigning' your application within reasonable limits have the same problem still reoccuring, you could do one of two things:
Either cange to a recognised brand of proven designed centric or double eccentric BFL valve (I presume centric BFL valve is what you have) for your exact application, with actuator from the same supplier. The problem is well known and with a correct total design you will have a better chance avoiding trouble.
The second option is to change to electrical actuators. Good electrical actuator brands for theese small valves will have considerable higher price than pneumatic actuators (approx 3 to 5 times higher), but should be considered for soft opening and closing actuation, and no air consumption.
RE: 3" throgh 6" rubber seated butterfly valve popping out of seat
Raising your air pressure or increasing the actuator size both contribute to actuator "Stiffness" and will reduce the effect/magnitude of the "pop". Unless you are using the valves for modulating service the pop is merely annoying and is not harmful unless it keeps the actuator from opening the valve at all.
RE: 3" throgh 6" rubber seated butterfly valve popping out of seat