Is it possible to not have a b allcock in a cold water header tank?

[Neil23]

For reasons that I won't go into.
Is it possible to control the water flow to a cold water header tank without having a ballcock in the header tank? ie to place some sort of control elsewhere in the feed pipe before the water gets to the header tank - turning off the mains water supply would obviously do this - but is there a way to control the water supply to the header tank other than turning off the mains?

 

[Basher]

Well it's possible, though the scheme might introduce other issues.
For example you could fit a motorised valve in the feed pipe somewhere, and fit a level switch in the tank, and wire the two and a power supply together. It would probably need to have a normally closed valve, meaning in a power cut the tank would not fill when needed.
If you were trying to reduce noise, the above could make things worse as there would still be filling sounds (possibly louder unless you reduce the flow) and the motorised valve might make a noise.
Many things are possible if you throw enough money at them. If you could indicate what your trying to achieve that might help with suggestions.

 

[Last Plumber]

There are float switches instead of mechanical float operated valves or there are sensors that pass a current and allow a solenoid to be opened and closed but without you going into why you need an alternative, there's no way of knowing what you're aiming at and why.