Surge Tank for the New Water Lines

The new water lines are working great when we are connected to the city’s water pressure but I ran into a problem when we left the dock and switched the water system over to the pump that we have on board.

The on board water pump takes water from our tanks and provides water pressure to push the water to our faucets.  It has a pressure switch attached to it so when the pressure reaches 65 psi it shuts itself off and when a faucet is opened, the pressure drops and the pump will automatically turn itself on.

The problem is that the old water lines had some stretch to them so they would expand like a balloon.  When a faucet was opened the water lines would shrink to their normal size and then the water pump would turn on.  This expanding and shrinking of the water lines caused a natural delay for how often the water pump turned on and off, about every 5 seconds.  This was a good thing.

The new water lines have no flexibility to them and the water pump was turning on and off about every half second.  This is not good.  To cure this I made a water pump surge tank and installed it into the water system.

The surge tank is upside down in the picture.  Basically it is PVC piping with a valve on it.  This device was attached to the water system.

When the water pump is on, it forces water into the bottom of this tank.  As it fills the tank, air trapped above the water will become compressed.  When the pressure reaches 65 psi the pump turns off.

When a faucet is opened, the water level in the tank must drop several inches before the pump will turn back on.  This causes a nice delay from when the electric water pump turns on and off.  We are now back to the 5 second interval from when the pump turns on and shuts itself off.