What are Pressure Tank and Expansion Tank? ｜Aquasky
A pressure tank is a maintained device for water pressure. There is an air pre-charge inside like car tires. The air pressure inside the pressure tank is separated by a rubber diaphragm with the water pressure to maintain the water pressure in the system.
Pressure tanks are most often used in domestic waterworks applications. Their main function is to balance and maintain constant pressure in the water distribution system. A pressure tank can store a good amount of water to protect your pump from frequent switching, which leads to rapid could wear. The user may only wash their hands or flush the toilet, and the water pump does not need to start. The water can come from the tank. It is an energy-saving device and a protection device in a water supply system. Based on the system size, it could be 0.5L to 2000L tank.
The expansion Tank is usually much smaller compared with the water supply pressure tank. The expansion tank is used to absorb the water or thermal liquid expansion. The temperature change can cost the water volume expanding and create the water pressure changes in a closed system same as other liquid. The extra volume of water or liquid can damage the piping or the handing structure of the system which creates a lot of leakage of the system.
The Expansion Tank has an air-per charge inside the tank is separated by a rubber diaphragm with the liquid pressure. The air zoon of the expansion tank can be compressed which is a soft zoon in the system, so it can store the extra volume of the water or the thermal liquid due to the temperature change to avoid the water pressure suddenly rising to damage the water valve or piping connection.
The difference between Pressure Tank and Expansion Tank
The tank is in a water supply system used for the storage water and the protection of the water pump. This is a Pressure Tank.
The tank in a water heating or liquid heating system is used to absorb the liquid expansion Hydraulic pressure. This is an Expansion Tank.