Fir currently has two functioning systems for pumping domestic water. Each is configured with centrifugal pumps tied to the water manifold. These pumps were designed to rapidly move water between tanks, and then from tanks to a lighthouse. Since both units are in fine working order, we see no reason to replace them.
Our on board water system is much like a set up for residential well water. We have two devices that pump water from one tank (usually the galley tank) into the pressure tank, it compresses the air in the tank until it reaches a preset level, typically the 40 to 60 pounds per square inch (psi). When someone turns on a faucet, air pressure in the tank forces water throughout the plumbing until the pressure drops to the preset trigger pressure, usually the 20 to 40 psi. That tells the water pump to turn on, and water is then drawn into the tank. When the faucet is shut off, pressure builds until it is restored to its default shut-off level. The amount of water delivered by the pressure tank between the time the pump shuts down and the time it starts again is called the drawdown.
At the moment only one of our existing pumps is operative, and pressure control has proven unreliable. Since fresh water is so critical, a new system must be installed. We are looking at variable speed drive pumps to meet our fluctuating demands. These are multistage pumps able to adjust speed and maintain 70lbs or more of pressure at various volumes. This type of system will allow us to sustain domestic water pressure even while washing down the deck
There are several companies that offer the right kind of pump. Click here to see how we selected the pump system.