My next batch of mods will include a normally open 12v solenoid on the mains pressure pipe just inside the van under the lounge behind the filler box.
I going to attempt to connect it into the Drifter pump switch, maybe via a relay, so i can switch on the pump and isolate the mains pressure with one button.
The relay would only require power to close, remaining open and inactive the majority of the time, and considering the possibility that if the solenoid fails we only end up with exactly what we now have anyway
That way i can easily get at my tank water from inside the van without disconnecting or turning off the main pressure hose. (we drink a lot of water and use van tanks primarily for keeping our precious drinking water, that at the moment i cant get out unless i disconnect the damn mains hose)
Not sure how solenoids would work on the tank lines ... would it best to have open or close solenoids? Either way, one solenoid would always need constant power.