replacement electric actuator & controller for butterfly valve tank-to-pump
Anyone know of an inexpensive kit or parts to replace a pneumatic butterfly valve acutator with an electric actuator that can be opened partially? We have a pneumatic tank-to-pump which is causing problems when trying to use the venturi principle to pull a draft when switching from tank water to draft (this is how we operate as we have 0 hydrants and not enough staffing/apparatus for a nurse pumper operation). the problem is the pneumatic valve opens/closes in under a second and causes a sort of water hammer on the pump from the sudden vacuum condition. With our older pumper we have a manual tank-to pump, so we are able to close this slowly to achieve a vacuum from the tank, and then crack open the steamer intake to venturi the air in the hard suction, achieving a seamless transition. Close the T2P a bit, open the intake a bit, repeat, repeat, etc.
We are using an electric governor, so the sudden mass introduction of air causes a temporary loss of prime, even when "feathering" the switch rapidly and laying on the primer. A primer before the intake valve is not possible as the valve is external gated Siamese (we use dual 3" intakes). The feathering works, but i believe it is very hard on the pump, and am afraid it will cause the switch and/or pneumatic actuator to fail prematurely.
All i want to do is replace the actuator, as this engine is a plumbing nightmare. I have contacted the builder to see if they can locate an inexpensive suitable replacement with the necessary controller.