Water Pressure Tank Sizing Chart

Water pressure tanks store water that s pumped from a well and dispense water under pressure when you use faucets and other fixtures.

Water pressure tank sizing chart. The figure that is calculated on line 7 is the total tank volume required based on the given design criteria. Properly sizing a water pressure tank ensures that the run time on the water pump is kept at a minimum. A pressure tank is an integral part of maintaining your well. Join john woodard our master water specialist.

The calculation to determine stored water requirement drawdown is. This should not be confused with tank volume for example a pre charged tank with a tank volume of 20 gallons has only five to seven gallons drawdown capacity depending on the cut in cut out on. Almost 2 3s or more of a tanks. You will want to choose a tank with the lowest volume capacity that is greater than or equal to the total required volume.

With the water pump off the pressure in the tank will remain at 60psi until more water in the house is used draining the tank once again. The amount of water stored in a vessel between high and low pressures is commonly called drawdown and the high and low pressures are dictated by the size of the tank s air cushion. A 20 gpm pump needs a tank with 20 to 40 gallons of storage. Larger tank sizes will reduce pump cycles extending pump life and saving electricity.

Pressurized well tanks extend the lifespan of your well pump by preventing rapid on off cycling of the pump and maintaining water pressure throughout your home. A larger pressure tank can often be a good way to extend the life of your pump and electric motor provided that you have enough space to accommodate a larger tank and where the flooring can hold the additional weight. There are no disadvantages to having a larger well tank. Once the pressure in the tank meets the 60 psi threshold pump cut out pressure the pressure switch will signal the water pump to stop pumping ceasing the influx of water into the tank.

Tank drawdown capacity is the minimum amount of water stored and or delivered by the pressure tank between pump shut off and pump re start. Old pressure tank sizing method in the past pressure tanks were sized to store at least 1 or 2 gallons of water for every gallon per minute the pump can produce. A properly sized pressure tank ensures your household water needs are met and your pump is protected against short cycling. Sizing a water pressure tank properly keeps the amount of run time to the water pump held to a minimum.

To select the minimum size tank count the fixtures inside and outside your home including showers appliances toilets etc and refer to the chart below. The more a pump must run the more wear and tear occurs to the pumping mechanism and the electric motor. A 10 gpm pump needed a pressure tank that holds 10 or 20 gallons. It s important that the size of a tank is adequate for your.