A tank can be viewed as a bag of air. The goal in sizing a tank is to make the bag of air large enough so that when the desired amount of water is put in the tank the air is not compressed to a pressure greater than system design.
How do I size a tank?
Select a PDF help sheet from our list of tanks below for assistance in sizing your pressure vessel.
- Plain Steel Expansion Tanks
- Bladder Expansion Tanks
- Diaphragm Expansion Tanks
- Hydropneumatic Tanks
- Size a Hydropneumatic Tank Help Sheet (Excel File)
- Acceptance Factor Chart
- Water Expansion Table
Wesselect Tank Sizing Software
You can download our custom tank sizing software (Windows only) for help sizing your tank, too.
Download Now (32 MB)
What is “Acceptance Volume”?
Acceptance Volume: This is the volume of water a tank is designed to hold. If in a bladder tank, a bladder smaller than the tank size is used, the acceptance volume would be what the bladder is designed to hold. Keep in mind that the tank has air contained in it and therefore it is not possible to fill the entire tank with water.
Some bladder tanks have a stated “full acceptance volume.” This means that if there is a loss of air in the tank, the bladder would be able to accept the full tank volume without permanent damage.