Booster Pump Systems
Booster pumps are used to draw water from storage tanks and supply pressure and volume as needed. Booster pumps are also used to draw water from a low pressure line, such as a city supply, and boost the pressure as needed.
Boosting from storage tanks
A centrifugal or jet pump can be attached to a water supply line at the bottom of a storage tank. A submersible pump can also be installed inside a storage tank and used as a booster pump. A booster pump draws water from a storage tank and supplies water at the flow and pressure needed. Controls for a booster pump can be similar to controls for a well pump. A booster pump can be controlled by a pressure tank and pressure switch, with a Cycle Stop Valve. Controls for a booster pump should be able to deliver water on demand when a tap is opened, and turn off the pump when no water is being used. As with a well pump, a booster pump system must be able to produce enough flow for peak demands, as well as deliver minimum flow rates when required. Dry run protection is recommended to keep the pump from melting down in cases where the storage tank runs empty. The same low amperage or low pressure devices used on well pumps can also be used to protect booster pumps. A float switch at the bottom of the storage tank can also be used to prevent the pump from running, when the water level in the storage tank is below the float switch.
Boosting from city water lines
As long as the city water line can supply an adequate volume of water, a booster pump can be connected directly to the water line to increase pressure as needed. Generally it is easier to connect a centrifugal or jet pump to an incoming water line. However, a submersible enclosed in a can is also able to connect to an incoming water line and can be used as a booster. When the incoming water line is too small or corroded to supply an adequate volume of water, a storage tank can be used the same way as it is used with low producing wells. Either way a booster pump must be controlled similar to a well pump. Dry run protection can be added the same way as with Well Pump Controls.
Jet pumps and multi-stage centrifugal pumps are the most common type of pumps used to boost pressure. These pump have the same problems as any other pump when controlled with a VFD. Other booster pump controls use flow switches, shuttle valves, or combinations of both, and many claim to be "tankless". One of the main problems with these type controls, happens when there are small leaks such as a dripping faucet or a seeping toilet flapper. Small leaks will cause these type booster pumps to cycle on and off rapidly until the pump is destroyed. A standard jet pump without any electronic controls, using a CSV, pressure switch, and small pressure tank is less expensive and more dependable than so called "tankless" pump control systems.