Your air compressor tank is a key component in ensuring that your entire compressed air system runs efficiently. Having adequate air storage for your application is crucial in making sure that you achieve the best results possible. That is why it’s important to consider how to size the compressed air tank as you build the system that’s right for your business. If you’re in manufacturing, sizing can be extremely important for your business.
Below is the information you’ll need in order to size the compressed air tank for reciprocating compressors, stationary compressors, or rotary screw compressors. But first, let’s look at some general guidelines for tank sizing.
General Guidelines For Air Receiver Tank Sizing
The volume of compressed air storage that you’ll need within your facility will depend on these four factors:
- What is the capacity of your air compressor in cubic feet per minute (CFM)?
- What are the peak CFM requirements at the maximum demand?
- What is the consistency of airflow?
- What is the diameter of the piping?
As you look to determine air compressor size, a good guideline is that 1/3 should be wet and 2/3 should be dry storage. Below is more information on sizing for different types of compressed air storage.
Sizing An Air Receiver Tank For Reciprocating Compressors
Reciprocating air compressors require the use of an air receiver tank for storage and to eliminate pulsation. The tank needs to be filled with enough air for the tools or necessary equipment to run. Proper sizing is important so that you do not have to stop using the necessary tool to wait for the tank to refill.
There is a formula that can help you to get the proper size tank. You’ll want to take the tool with the highest CFM requirement at the required PSI, and multiply that by 1.25 or 1.5 and round up to the nearest gallon size.
Here’s what that looks like:
CFM X 1.25 (then round this up to the nearest gallon size) = recommended tank size in gallons
CFM X 1.5 (then round this up to the nearest gallon size) = recommended tank size in gallons
When you use this formula, it may not eliminate the need to wait between tank fills, but it will certainly reduce the amount of times that’s needed.
Sizing A Receiver Tank For Stationary Air Compressors
Sizing an air receiver tank for custom stationary applications is more complex and should be done by a qualified engineer. The sizing should be done by volume and pressure variations, air compressor size, pipe or hose size and length, and the control system strategy all in mind.
The formula for this is more complex:
T=V(p1-p2)/C Pa
t= Time for receiver to go from upper to lower pressure limits (in minutes)
V= Volume of the receiver tank ( cu ft)
C= Free air needed
pa= Atmospheric pressure (14.7 PSIA)
p1= Maximum tank pressure (PSIA)
p2= Minimum tank pressure (PSIA)
PSIA = Pounds per square inch absolute; the pressure relative to a vacuum.
Again, this is a more complex equation and in order to get the most out of your air compressor, a qualified engineer should be the one to determine the appropriate size for an air receiver tank on a stationary air compressor.
Using An Air Receiver Tank For Rotary Screw Compressors
Many rotary screw compressor applications don’t require the air tank. There’s a continuous stream of compressed air available without pulsation. The only time that an air receiver tank benefits you is if the tool in use requires more CFM than what the air compressor produces.
Some compressed air users might want to use an air receiver tank to simply give their higher CFM tools a boost. Let’s say an auto mechanic requires a 40 CFM tool with a 30 CFM air compressor. Adding a 12-gallon receiver tank would help to compensate for that difference. This strategy can allow businesses to make do with a smaller compressor.
Do You Have Sizing Questions For Your Air Compressor?
Sizing the air receiver tank for your compressed air system can be a complex undertaking. If you have questions or would like to discuss your system, it’s good to talk with a company that’s experienced in air compressor sales so that you can be sure you’re getting the right information. Contact us today, and we can help you get started!
