FS-Curtis RNPX Series

RNPX is a non-cycling refrigerated air dryer line covering roughly the 150 to 400 CFM band. It sits in the mid-capacity range, suited to larger shops and light industrial compressed air systems where a small shop dryer would be overwhelmed at peak flow.

Both are non-cycling refrigerated dryers. RNPX covers a specific mid-range flow band within the broader family. Where the ranges overlap, the choice comes down to configuration, footprint, and connection arrangement rather than a difference in drying approach.

A 150 to 400 CFM dryer generally pairs with larger rotary screw installations rather than a single small reciprocating unit. Size on the actual delivered SCFM at your working pressure, including any planned future capacity, rather than on compressor horsepower.

It needs to handle at least the compressor's full delivered flow at your operating conditions. Slight oversizing is normal and harmless; undersizing means moisture carries through at peak flow. If you plan to add compressor capacity later, sizing the dryer for that now avoids replacing it.

Compressor, then aftercooler, then particulate filter, then dryer, then coalescing filter, then distribution. Adequate clearance around the condenser and ambient temperature within the model's rating are both required for the unit to reach its rated performance.

Clean the condenser on a regular interval, verify the condensate drain actually discharges, and watch for a rising dew point as the earliest indicator of trouble. A failed drain is the most common issue on any refrigerated dryer.

That's not the case. Standard refrigerated dryers require inlet air within a specified temperature range. Feeding uncooled compressor discharge into one overwhelms it and moisture passes straight through. Either install an aftercooler ahead of it or specify a high-inlet-temperature model.