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
Dryer: 0.2 bar
Maintain. unit/hose: 0.5 bar
Total: 0.8 bar
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.
For expert advice on your compressed air system, contact KAESER today. Just phone 0800 447 820 or fill in our form below - and we’ll get back to you.