Originally Posted by BOOZE TRAVEL
Will the brass fitting in the picture pull suction from a water bladder?
We will be boondocking after Christmas and intend to use a water bladder to refill when I donít feel like moving the coach!
That will pull water from an outside container, but it won't refill your fresh water tank
if that's what you intended.
As posted, it is used to winterize the system. Turning the valve to INLET connects the fitting in your picture to a point between the fresh water tank pipe and the pump, but that point shuts off the flow of water from the tank to the pump and replaces it with the connection to the inlet.
Drawing water in through the inlet and then through the pump will fill the system and pressurize it, but no water will flow into the tank because of the CITY WATER valve. If it's set to CITY, it isolates the pipes in the system from the fresh water tank. If it's set to TANK FILL, the pipe to the fresh tank is open only to the outside fitting for filling, not to the pipes from the system that are fed by the pump.
I suppose it's possible to move the CITY water valve part way between the two positions, creating a "leak" at the valve itself, allowing pressurized water from the pump/system to leak back into the tank. It will not come out the CITY fill connection due to a check valve.
Look at this diagram, specifically the upper right corner and the area by the pump. Your system is probably similar.