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Q. What is a Pressure Tank and How Dose it Work?
There are two types of tanks used for residential water systems; air over water tanks, and precharged tanks.
A tank works when water is pumped into
it, which compresses the air inside, giving the water and air increased
pressure. A check or foot valve is placed in the water line before the tank
to prevent the increased tank pressure from escaping back down the well.
The difference between an air over water tank and a precharged tank is that a precharged tank has a bladder or other impermeable device that separates the air from the water. An air over water tank allows the air and water to touch and mix.
The pressure in the tank regulates a pressure switch that in turn turns the pump on and off. It is essential that the tank have the correct amount of air pressure in it to properly control the pressure switch. If the air pressure in the tank is set to high there is less that normal water capacity in the tank. This causes the pump to run more frequently and for shorter durations to replace the low quantity of water on the tank. If the air pressure in the tank is set to low there is more than normal water capacity in the tank. This causes the pump to run less frequently and for longer durations to replace the high quantity of water in the tank. Stress on the tank is also increased, which causes damage to the tank.