I need to find a valve, or some technique to heavily constrict the flow of water in a 4cm pipe. Pressure is low coming from a 2m cistern head above.
I have been searching in vain for a very cheap PVC butterfly valve with poor closed sealing characteristics, but with no luck. I did have a little more success with gate valves like this one
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but as I need to actuate the valve from a small motorised actuator I am concerned about the force required to open/close the gate.
I am open to any valve technique provided it costs well under ten pounds in quantity.
Does anyone have any suggestions as to where I might find a very inexpensive plastic valve for this project?