Donaldson DF-C 0050-1450 Compressed Air Cyclone Separator

A cyclone separator that removes liquid before the fine filters

The Donaldson DF-C 0050-1450 is a cyclone separator for compressed air and gases. It has no filter element: an insert in the cyclone head spins the incoming air so that droplets and larger particles are thrown against the housing wall, run down and collect in the sump, from where the condensate drain removes them. Donaldson places it downstream of an aftercooler or ahead of high-efficiency filters, where it takes the bulk liquid load off the elements behind it.

Eight sizes cover 50 to 1,450 m3/h at 7 bar(g). The housing is immersion-lacquered inside and outside against aggressive condensate, and a bayonet lock joins head and bowl so it cannot be opened under pressure.

Technical specifications

Sizes and pressure loss

• 0050: Flow m3/h 50; Port G 3/8; Weight kg 0.78; Differential pressure mbar 95
• 0120: Flow m3/h 120; Port G 1/2; Weight kg 1.12; Differential pressure mbar 60
• 0210: Flow m3/h 210; Port G 3/4; Weight kg 2.18; Differential pressure mbar 50
• 0320: Flow m3/h 320; Port G 1; Weight kg 2.18; Differential pressure mbar 65
• 0450: Flow m3/h 450; Port G 1 1/2; Weight kg 5.32; Differential pressure mbar 40
• 0750: Flow m3/h 750; Port G 2; Weight kg 5.32; Differential pressure mbar 55
• 1100: Flow m3/h 1,100; Port G 2; Weight kg 5.32; Differential pressure mbar 70
• 1450: Flow m3/h 1,450; Port G 2 1/2; Weight kg 5.32; Differential pressure mbar 130

Sizes 0210 and 0320 share one housing, as do 0450 to 1450; the larger sizes differ in port and, for 1450, in the head width. Note that the lowest pressure loss in the table, 40 mbar, belongs to the 450 m3/h size.

Standard or Superplus drain

The standard unit carries a time-controlled UFZ drain, which opens on a timer whether or not condensate has collected. The Superplus version replaces it with the UFM-D level-controlled drain, which opens only when the sensor sees liquid and so does not blow compressed air. For a station with a high condensate rate, the level-controlled version is the one that avoids the air loss.

Typical position in the air line is directly after the aftercooler or receiver and before a DF or SG coalescing filter. Donaldson lists chemical, pharmaceutical, surface finishing, machine building and power plants among the industries. Optional extras are a wall bracket with a wall distance that can be set steplessly and a connection adapter so that a cyclone separator and a filter housing can be joined without extra pipework.

Choosing the right DF-C size

Size the separator from the actual compressed air flow and operating pressure of the line, not from the pipe size alone. Take the delivery of the compressor or compressors feeding the line, convert it to the reference conditions used by Donaldson, and correct for the real working pressure if it differs from the nominal value. Choosing a size that runs close to its nominal flow keeps the cyclone effect strong, while a heavily oversized unit may separate less effectively at low velocities. Check that the port size suits the existing pipework and that the maximum operating pressure and temperature of the system stay within the limits listed above.

Installation and commissioning

Install the separator vertically with the bowl pointing down, in the direction of flow marked on the head, and at a point where condensate naturally collects, such as directly after the aftercooler or the air receiver. Leave enough space below the bowl to open the bayonet lock and remove it, and support the pipework so that its weight does not rest on the housing. Run the drain outlet to a suitable condensate collection or treatment system, because compressor condensate contains oil and must not be discharged to drains or soil without treatment where local rules forbid it. Before pressurising, check that all joints are tight and that the drain is connected and powered where required. Then bring the system up to pressure slowly, check for leaks and confirm that the drain discharges condensate as expected.

Operation in hot, humid Gulf conditions

Compressed air systems in Oman and the wider GCC work hard in summer. High ambient temperatures and humidity mean the intake air carries a large amount of water vapour, and much of it condenses after the aftercooler, so the liquid load reaching the separator is often heavy. This is where removing bulk water before the fine filters and dryer pays off, since it protects the coalescing elements from flooding. Place the separator in a ventilated, shaded part of the compressor room, as hot compressor rooms can approach the upper temperature limit of the housing. Dust from desert sites drawn into the compressor intake can also travel downstream, so keep intake filters well maintained.

Routine maintenance

Because there is no element to replace, maintenance centres on the drain and the housing. Check daily or at each shift that condensate is actually being discharged from the drain, and investigate promptly if liquid starts to collect in the bowl or water appears in the air line downstream of the filter. During planned shutdowns, depressurise the line, open the bowl, clean out sludge and inspect the seals and the internal surfaces.

Documents and quotation

For a written offer on DF-C 0050-1450, use the form. the flow size, port and drain type must be confirmed against the attached Donaldson DF-C cyclone separator data sheet (F119059, 12/2025) beforehand. Explore Filter Housings.