What is the pressure tank for?
Pressure tanks of various sizes are used to supply water pressure even when the submersible is stopped. A pressure tank is cylinder shaped, made of steel or fiberglass, and is generally about four feet tall and two feet in diameter. Inside is a rubber bladder, which takes up about half of the capacity of the tank. The remainder of the tank (usually the top portion) is air space. When the submersible is running, water is pumped into the bladder. As the bladder fills, it enlarges, causing the air in the space above to become compressed (the water itself cannot be compressed). Once the bladder is full, a pressure switch shuts off the submersible. When a faucet is opened, water flows out of the bladder, pushed by the compressed air. After a certain quantity of water is used, the bladder is near empty, and the pressure switch activates the submersible again to cause the cycle to start over.
