Water Pressure Booster Pump & Tank Systems
InspectAPedia^®  -    

• Guide to Pumps & Pressure Tanks Used to Boost Water Pressure in Buildings
• Adding a water pressure boost pump to private, community,or municipal water supply
• Adding a water pressure boosting pump to private well, cistern, or spring systems

• Homes at the end of a water supply line: Community water supply systems serving just a few or even many homes, but with some homes near the end of the system
• Buildings located high above a water supply line: or located far uphill from the pumping station receiving only modest incoming water pressure, perhaps less than 30 psi.
• Tall residential properties requiring additional water pressure to serve upper floors. For a tall home connected to a community water supply providing incoming water at only 30 psi, for example, the top floor may see 17 psi unless a booster pump and pressure tank are installed. (Very tall buildings such as skyscrapers and offices and multi-story apartment buildings are more likely to install a rooftop water supply tank which is fed by a pump from street level but which in turn provides water down through the building by gravity.) Sketch, courtesy of Carson Dunlop
• Gravity water systems: Community water supply systems serving many homes but supplying water only during certain hours of the day, or only at very low pressure. For example San Miguel de Allende, Mexico, with a population of about 100,000 people, is served by nine water wells and pumping stations. But water is delivered to most homes by gravity, and in some seasons, only at certain hours of the day. A photo of a rooftop water storage system of this type can be seen at Rooftop Water Systems.

Our sketch, courtesy of Carson Dunlop and edited by the author shows a simple one line jet-pump and pressure tank connected to the incoming water line in a building. Our photo at page top shows a typical water pressure booster pump and tank system for sale at Don Pedro's Ferreteria in San Miguel de Allende.

The incoming community water supply line which normally is fed through a pressure regulator and into building supply piping is first connected to a water pump, usually a 1-line jet pump. The pressure regulator control is not shown in this sketch.

The water pump is in turn connected to a pressure tank, possibly a large one to give a good high pressure water supply to the building.

As water is drawn into the home (someone turns on a faucet) the pressure tank feeds pump-boosted water pressure to the building, and as water pressure drops in the water tank, the jet pump draws more water from the community supply line, boosting its pressure into the pressure tank.

Typically the booster pump pressure control switch will be set to operate in the 30-50 psi range, providing good water pressure to the building.

In a private well water supply system this pump and tank combination may be connected directly to the well, that is, the incoming water line shown in the left of the sketch is connected to a foot valve immersed in the water well. at WATER PUMP, ONE LINE JET we discuss one-line jet pumps in more detail. at WATER PUMP CONTROLS & SWITCHES we discuss the pump pressure control switch and how it can be adjusted to provide higher water pressure.

What kind of water pressure booster pump do we need?

The reason that a typical residential property needs just a one-line jet pump to provide its water pressure boost is that there is already water arriving at the building under some pressure - the pump does not have to combine lift of the water from deep in the ground to high in the building.

Our photo of a pressure booster pump and tank system at left (and at page top) shows that stainless steel parts were used to enclose the pump parts: this system is designed for outdoor use in a non-freezing climate. You can see the pressure gauge and the gray box housing the pump pressure control switches above the stainless-steel covered pump assembly itself.

Do we need a more powerful water pump or larger diameter water supply piping?

Some water pressure booster applications may require a more powerful pump than the type we discuss here, particularly if the anticipated water flow or usage rate in the building is high.

Carson Dunlop's chart at left explains that in an individual plumbing system (that is, changing nothing but water flow rate), the water pressure observed at a fixture (and in the piping) will drop off significantly as the water flow rate increases.

This chart explains why the water pressure in your shower may fall off substantially during your bathing if someone else in the building flushes a toilet or turns on the dishwasher.

The chart also demonstrates that using larger diameter piping for the water supply in a building can significantly reduce the pressure drop when multiple fixtures are running at the same time.

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