KAESER Know How blog post: How to energy efficiently ensure the correct air pressure at the air connection
KAESER Know How Blog

What do you do if your compressed air pressure is too low at the take-off point in your system? Do you just set the station pressure 1 bar higher to compensate? In this blog post we identify how you can get the correct pressure at the air connection while avoiding this costly pitfall.

Don’t waste your energy!
KAESER Know How Blog

What do you do if your compressed air pressure is too low at the take-off point in your system? Do you just set the station pressure 1 bar higher to compensate? In this blog post we identify how you can get the correct pressure at the air connection while avoiding this costly pitfall.

Don’t waste your energy!
Don’t waste your energy!

Quick tip: How to energy efficiently ensure the correct air pressure at the air connection

November 2020

What do you do if your compressed air pressure is too low at the take-off point in your system? Do you just set the station pressure 1 bar higher to compensate? That may seem like a quick and easy fix. But, did you realise that for every pressure increase of just 1 bar - the energy consumption of the compressor station increases by 6% - and, the leakage rate also sharply increases. That’s a lot of additional and wholly unnecessary cost. In this blog post we share a tip from our Compressed Air Engineering Handbook which identifies how you can get the correct pressure at the air connection while avoiding this costly potential pitfall.

The compressor station pressure is actually correct, but pressure is too low at the air-consuming equipment. What’s the cause? 

In this case, hoses, quick couplings and pressure regulators are commonly the offending components. But often the pressure at the take-off point in the system is too low: for example, of the 6.8 to 7 bar originally available for the tools, a mere 5 bar remains. 

Operators often turn to a quick fix: “Let’s just set the station pressure 1 bar higher, who cares!” But this is problematic, because for every pressure increase of 1 bar, the energy consumption of the compressor station increases by 6 % – and the leakage rate also sharply increases. It’s therefore advisable to identify the causes and implement an appropriate solution. 

Pipe network as the source of the problem
When the pressure directly downstream of the compressor is correct and there is no disproportionately large reduction due to downstream treatment components, the problem can only be in the pipe network. This is divided into three sections: the main line, distribution line and connection line. In an optimised compressed air system, the following pressure drops are reasonable from an efficiency perspective: 

Main line: 0.03 bar
Distribution line: 0.03 bar
Connection line: 0.04 bar
Additionally:
Dryer: 0.2 bar
Maintain. unit/hose: 0.5 bar
Total: 0.8 bar 

Eliminate ‘bottlenecks’
Upon closer inspection, it often becomes apparent that although the main line and distribution lines have the correct dimensions, the connection lines are too narrow. For these, the pipe width should not be less than DN 25 (1”). For precise determination of the cross-section, use the pressure drop calculator that can be found in the KAESER Toolbox - click here

Furthermore, a specialised nomogram can also be used - download the complete Compressed Air Engineering Handbook and see page 54 - click here 

Ensure correct connections
To prevent disruptions and damage due to potential moisture, the connection between the distribution line and connection lines should be designed beginning with a flow-optimised “swan neck”: a direct downward pipe should only be used if the possibility of condensate formation in the pipeline can be excluded with 100 % certainty.

Need some advice?

Kaeser Compressors sales and engineering

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