A pressure tank is required in a farm water system to maintain pressure in the system when the pump is not in operation. The amount of water that can be taken from the system between pump cycles is called the "draw off." Pressure tanks should be sized so that the pump will not cycle more than 25 times per hour. This set-up allows approximately 1 gallon of draw off for every 100 gal/hr pump capacity. For example, if a pump produces 600 gal/hr (10 gal/min), then the pressure tank should have a draw off of at least 6 gallons. The specification charts provided with the pressure tank will give the draw-off capacities at different pressures.

A pressure tank is required in a farm water system to maintain pressure in the system when the pump is not in operation. The amount of water that can be taken from the system between pump cycles is called the "draw off." Pressure tanks should be sized so that the pump will not cycle more than 25 times per hour. This set-up allows approximately 1 gallon of draw off for every 100 gal/hr pump capacity. For example, if a pump produces 600 gal/hr (10 gal/min), then the pressure tank should have a draw off of at least 6 gallons. The specification charts provided with the pressure tank will give the draw-off capacities at different pressures.