Water in compressed air lines is the most common complaint about air systems. The root cause is almost always insufficient drying or drainage, and the fix is a complete treatment train rather than a single component.
Why water appears
Ambient air contains water vapour, and compressing it concentrates that moisture. As the air cools in the pipe, the vapour condenses. If the system lacks an aftercooler, dryer and working drains, that liquid water reaches the tools.
Common causes
- No dryer or an under-sized dryer
- Failed condensate drain
- Dryer bypassed or running above its rated temperature
- Long outdoor pipe runs with no low-point drains
The fix
Install the correct aftercooler, water separator and dryer in order, and make sure every drain works automatically. Slope the piping to drain points, and verify the dryer outlet dew point meets the process requirement.