Condensate Management

Centrifugal Moisture Separator

Water thrown out of your air the moment it forms, with nothing to replace and nothing to plug in.

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Two flanged centrifugal moisture separators with pressure gauges, beside their swirl insert

Product overview

Take the water out where it first appears

Our centrifugal moisture separator spins your compressed air so the liquid water, the oil carried with it and coarse dirt are flung against the vessel wall, run down into a sump and leave through an automatic drain. It has no filter element and needs no power: the shape of the vessel and the speed of your air do the work.

Fitted straight after your aftercooler, it catches the largest liquid load in your system. Air drawn in at 25 °C and 60 % RH, compressed to 7 bar g and cooled to 35 °C condenses about 8.6 g of water per cubic metre of free air: around 124 litres a day from a compressor delivering 10 m³/min.

It removes droplets down to a few micrometres, and its pressure drop stays at typically a few tens of millibar at rated flow for the life of the unit. Your air leaves free of bulk liquid but still saturated, ready for the receiver, filters and dryer that follow.

A centrifugal moisture separator with its swirl insert, drains and mounting parts laid out around it
  • 8.6 g/m³Liquid water after a 35 °C aftercooler
  • About 340 gAcceleration on droplets at 10 m/s, 30 mm radius
  • Class 7ISO 8573-1:2010 liquid water, with 95 % removed
  • ZeroFilter elements to replace

Benefits

The problems it solves

Every compressor turns the water vapour it draws in into liquid. Here is what that liquid does downstream, and how the separator stops it.

  • Flooded filters and dryers

    The problem

    A slug of liquid floods a coalescing element, and liquid entering a dryer adds a water load it cannot remove, so the dew point rises.

    How it solves it

    Taking the bulk liquid out first keeps your filters and dryers within their design loads, so they deliver their rated air quality.

  • Rust in receivers and mains

    The problem

    Liquid water in carbon steel receivers and pipes forms rust, and the flakes block orifices and jam valve spools.

    How it solves it

    Liquid is removed at the compressor outlet, keeping water out of your receivers and mains.

  • Filter elements to buy

    The problem

    Elements load with dirt and must be bought, changed and disposed of.

    How it solves it

    There is no element at all. Service is drain upkeep and inspection, so your running cost stays low.

  • Creeping pressure drop

    The problem

    Each 1 bar of extra compressor discharge pressure raises compressor energy use by about 7 %.

    How it solves it

    With nothing to clog, pressure drop stays at a few tens of millibar at rated flow, unchanged over time.

  • Water slugs after start-up

    The problem

    Wall film builds up in low points and is swept forward as a slug when demand surges or a compressor loads.

    How it solves it

    The sump absorbs these surges and passes them to the drain instead of into a filter bowl or dryer inlet.

  • Undried lines to tools

    The problem

    On networks without a dryer, water washes out tool lubrication and spoils paint, blasting and textile work.

    How it solves it

    Separators at low points and ahead of machines keep water out of your tools, cylinders and spray equipment.

Where it’s used

From the compressor room to the point of use

Wherever a compressor runs, liquid forms after the aftercooler. The separator belongs there first, and wherever your air cools again along the network.

  • Robots welding a car body on an assembly line

    Automotive and surface finishing

    On spray booth supply lines and ahead of spray guns and blast nozzles, stopping water slugs that cause blisters, fish-eyes and flash rust.

  • A row of yarn winding machines in a textile mill

    Textiles

    Air-jet looms and texturing machines, where water in the jet spots, stains or marks yarn and fabric.

  • Wine bottles moving along a bottling line

    Food, beverage and packaging

    Bulk liquid removal ahead of the coalescing filters and dryers that deliver the air classes specified for food contact.

  • Blue plastic bottle caps in a moulded tray

    Plastics and PET blow moulding

    High-pressure separators after each cooling stage and intercooler, on systems at up to 40 bar g.

  • Electricity pylons and power lines at sunset

    Power generation

    Service air, soot-blowing air, ash handling, maintenance tools and the feed to instrument air dryers.

  • A naval warship at sea

    Ships, shipyards and offshore

    Starting, service and working air, where salt-laden condensate corrodes pipework and tools.

Also construction, mining and tunnelling, abrasive blasting, pharmaceuticals, oil, gas and petrochemicals, pulp, paper and steel, workshops and garages, rail and transport, and biogas, hydrogen, nitrogen and CO₂ lines.

How it works

Spin, separate, drain

Fixed vanes set your air spinning. The liquid, far denser than the air, is flung to the wall and drained away, while the air turns and leaves through the centre.

How a centrifugal moisture separator works: wet compressed air passes fixed vanes that set it spinning; droplets and coarse dirt, far denser than the air, are thrown to the wall, run down as a film past a baffle into a quiet zone and leave through an automatic drain, while the air reverses at the bottom of the vortex and rises through the centre tube to the outlet, free of bulk liquid but still saturated. Wet air in8.6 g/m³ · Class 9Swirl vanes ≈ 340 g at 10 m/s Wall filmBaffleQuiet zone Air out≈ 0.43 g/m³ · Class 7Centre tube Automatic drainCondensate to oil–water separator 12345Wet compressed airAir freed of liquid waterWater, oil and dirt

  1. 1. SwirlWet air from your aftercooler passes fixed, angled vanes that turn it into a rotating vortex. The vanes do no work of their own: the swirl's energy comes from the pressure difference across the separator.

  2. 2. SeparateAt 10 m/s and a 30 mm radius the acceleration is about 340 times gravity. Droplets and coarse dirt cannot follow the air and are thrown to the wall: a 5 µm droplet moves outward at about 0.24 m/s, against 0.71 mm/s under gravity.

  3. 3. CollectThe liquid runs down the wall as a film, passes the baffle and settles in a quiet zone below it, where the air is almost still and cannot pick it up again.

  4. 4. Air outAt the bottom of the vortex the air reverses, rises through the centre and leaves through the outlet tube, free of bulk liquid but still saturated.

  5. 5. DrainThe automatic drain discharges the collected water, oil and dirt to the condensate line and on to your oil–water separator.

Worked example at 7 bar g: 10 m³/min of free air drawn in at 25 °C and 60 % RH, cooled to 35 °C, with 95 % of the liquid removed.

Get the full details

Our brochure covers it in detail, and our questionnaire tells us what we need to recommend the right one for your plant.

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