Pressure dew point (PDP) is the temperature at which moisture condenses in compressed air at operating pressure. It is the key measure of how dry the air is, and it drives dryer selection.
PDP vs Atmospheric Dew Point
- PDP is measured at line pressure, not at atmospheric pressure.
- Compression concentrates moisture, so PDP is more demanding.
- A dryer rated at +3 °C PDP delivers much drier air than the number suggests.
Choosing the Right Dryer
- Refrigerated dryers reach +3 °C PDP for general industry.
- Desiccant dryers reach -20 °C to -70 °C PDP for critical processes.
- Match PDP to the coldest temperature your piping will see.
Why PDP Matters
- Water in lines corrodes pipes and damages tools.
- Moisture freezes in outdoor or cold-weather piping.
- Food and pharma applications need very low PDP.
What PDP do I need for general workshop air?
A refrigerated dryer at +3 °C PDP is enough for most general industrial tools and machines.
Talk to an Engineer
Contact Panrui with your flow, pressure and air quality requirements to get a recommendation and factory quote for your project.