The importance of correctly sizing air pipe diameter.


Without a doubt, the most direct route to a more efficient compressed air system is to look beyond your air compressor, focus in on your air pipe distribution system, and assess whether it is designed appropriately for your application. The more efficient your compressed air pipe system design, the more efficient your compressed air system.

So, what’s a properly designed and efficient compressed air pipe system design? There are a few principles at play, but it all comes down to utilizing a larger diameter air pipe, reducing T-fittings, and leveraging a looped, or parallel air pipe system design.

Why are we urging compressed air system managers/owners to first look beyond the air compressor at their air pipe distribution system? Unfortunately, most of the applications that our compressed air system auditors come across in the field exhibit an air compressor struggling to meet the demands of production, not because it is undersized, but because of problems found within the air pipe distribution system itself. These costly scenarios could easily be prevented by looking at the air compressor as one piece of the puzzle, and adopting what’s called a ‘total system approach’ to compressed air distribution system design.

how-to-save-money-by-installing-larger-diameter-pipe-in-air-system_how to save money

Every 2 psi in pressure-loss represents a 1% loss in energy-efficiency.

Compressed air has work to do, that work is done at machines and processes often far away from the air compressor. Compressed air energy is delivered to an application’s points-of-use through compressed air piping, and is measured in pressure (psig). Pressure loss is a reduction in pressure of compressed air as it moves through the distribution system from the air compressor to its point-of-use. Common sources of pressure loss are leaks, flow regulators, dirty filters, and under-sized distribution piping, for example. Pressure loss in an air system is energy lost for performing work - Every 2 psig of pressure loss represents the opportunity to save 1% in energy costs.

Most air systems are typically over-pressurized.

In an ideal compressed air system, we identify our pressure requirements at the ‘work’, or ‘point-of-use’, and then size the air pipe to deliver the required pressure to perform the ‘work’, with little-to-no pressure loss. In an inefficient system, we see air compressors needing to run at much higher pressures than what is actually required to perform the work.

If a compressor has to run at 120 psig to deliver 80 psig to it’s work, that system can be said to have a 40 psig pressure loss, or 20% energy waste.  Sadly, compressed air systems with undersized air piping and over-pressurized air compressors are becoming far too common.


What type of air pipe you install makes all the difference.

Air pipe materials can also drastically impact the efficiency of your compressed air system. Purpose built compressed air piping systems made of aluminum have a smoother inner wall, and consequently less pressure loss than traditional black steel pipe, with the added benefit of no rust or scale to foul pneumatic systems.

Poorly designed piping systems can also have a negative effect on the reliability and serviceability of air compressors:

  1. Higher pressures mean higher temperatures.
  2. T fittings at compressor discharges cause turbulence and backpressure.
  3. Turbulence & back-pressure oil carry-over and compressor control issues.

Have a closer look at your compressed air system, what pressure do you need at your machines, equipment and tools that use compressed air?  What pressure is your air compressor running at? Would a larger diameter compressed air pipe save you energy?  Want to be more efficient, but need help? Get in touch below, and we'll get back to you.