When pressurized water from the outside flows into the air sac of the air pressure tank, the nitrogen sealed in the tank is compressed. Based on Boyle Mariotte Law, when gas is compressed, its volume shrinks and pressure rises. Stop the water when the air pressure in the air pressure tank becomes equal to the water pressure. When the water is lost and the pressure reduces, the air pressure in the air pressure tank is larger than the water pressure. In this case, the air volume expands and squeezes the water out of the air sac to the system. The drainage stops when the air pressure and water pressure are equal again.
Composition of air pressure tank
The air pressure tank is comprised of four parts: tank body, air sac liner, water inlet/outlet and air supply port. The tank body is generally made of carbon steel with a coating of rust-proof baking varnish outside; stainless steel tank is also optional. The surface is the original color of stainless steel and the air sac texture is generally EPDM or butyl rubber. The precharged nitrogen between the air sac and the tank body is generally prepared before ex-factory. Customers may choose to charge or discharge based on the practical working condition upon use. In general, the precharged air pressure had better be half of the maximum system pressure.