SMC AFM30-03 Mist Separator 0.3 Micron 3/8 Rc

Removing oil mist that a standard filter passes

AFM30-03 is the size 30, Rc 3/8 mist separator of the SMC AFM series. A 5 micrometre line filter stops dirt but lets the fine oil aerosol that a lubricated compressor discharges go straight through; the AFM is designed to remove it, with a nominal filtration rating of 0.3 micrometre (99.9 percent filtered particle size). It is placed after a standard air filter (and downstream of any dryer – SMC advises against installing it on the dryer inlet, as this can clog the element prematurely) and ahead of instruments, pneumatic controls or spray equipment.

The code gives the AFM series and body size (AFM30) and the 3/8 port (03). Nothing after 03 means standard Rc thread, polycarbonate bowl, left-to-right flow and the standard name plate. Letters in the how-to-order table add a bracket (B), float-type auto drain (D), flow direction (R) and others, as in the current catalogue example AFM30-F03BD-2LR-D.

Technical specifications

How the rated flow limits the choice

The 450 L/min (ANR) rated flow applies at 0.7 MPa inlet. The catalogue warns that the rated flow varies with inlet pressure, and that the air flow should be kept within the rated value to prevent lubricant carry-over to the outlet side. If the machine draws more air than that figure, the next body size (AFM40, 1100 L/min rated) is the sensible choice rather than running the AFM30 beyond its rating.

The current SMC catalogue quotes the outlet oil figure for a new element with an oil mist concentration of 10 mg/m3 on the inlet side, so a heavily oil-carrying compressor line needs an AF series air filter installed as a pre-filter, which SMC also recommends to prevent premature clogging.

Installation points

Mount the unit with the bowl down, observe the flow arrow and install it downstream of an air filter and upstream of the regulator and any lubricator. Drain the bowl regularly or fit the float-type auto drain, and replace the element at the pressure drop or interval recommended by the manufacturer; the catalogue lists the element assembly as a replacement part.

The catalogue notes that bowl O-rings and other O-rings are slightly lubricated, a detail that matters if the air is later used for oil-free purposes.

Documents and quotation

The SMC AFM/AFD catalogue linked at the end of this page contains order codes, specifications, options and dimensions. Please confirm thread, drain type and bracket before ordering. See Regulators for further air-preparation products. Seven Star LLC is an independent supplier and quotes the exact code on request.

AFM30-03 Status and Current Successor

The AFM30-03 is the legacy code of this mist separator. SMC’s current catalogue lists the size 30 body as the AFM20-D to AFM40-D series, so the present-day equivalent of an AFM30-03 is the AFM30-03-D (Rc 3/8, polycarbonate bowl with bowl guard, manual drain cock, left-to-right flow). The values in the table above are taken from the current AFM-D data where a legacy figure could not be confirmed.

Additional AFM30-D data from the SMC catalogue

How the AFM30-03 Mist Separator Works

Compressed air enters the body and passes through the fine fibrous element. Oil aerosol droplets far smaller than a standard 5 µm filter can stop are captured by the fibres, merge (coalesce) into larger drops and run down into the bowl, where the condensate collects until it is released through the drain cock or a float-type auto drain. Because the element captures particles down to a 0.3 µm nominal rating, solid particles that reach it also accumulate, which is why an upstream AF filter is needed and why the element is a periodic replacement item.

With the float-type auto drain, a float lifts as condensate rises and opens the drain valve. The N.C. type (option C) keeps the drain port closed when no pressure is applied, so some condensate may stay in the bowl after shutdown; the N.O. type (option D) opens the drain when pressure is removed. SMC recommends the N.C. type for small compressors (0.75 kW, under 100 L/min discharge) because the N.O. drain can leak air at start-up.

Selection & Ordering Guide

The clogging switch options use a D-A93VL reed auto switch. If you are replacing an old AFM30-03 in a modular set, our team can help confirm the correct ordering code, including spacers and brackets for the AF + AFM + AR combination.

Replacement parts for AFM30-D

• Element assembly: AFM30P-060AS
• Bowl seal: C32FP-260S
• Bracket assembly: AF34P-070AS
• Bowl assembly (polycarbonate, drain cock): C3SF-D; with N.C. / N.O. auto drain: AD37-D / AD38-D

AFM30-03 Installation & Maintenance

• Install an AF series air filter as a pre-filter on the inlet side; do not fit the unit on the inlet side of a dryer.
• When refitting the bowl, line the lock button up with the groove on the front or back of the body so the bowl cannot drop.
• Replace the element every 2 years or when the pressure drop reaches 0.1 MPa, whichever comes first. With the M or MM clogging switch, replace it when the switch signals, even within 2 years.
• The polycarbonate bowl must not be exposed to organic solvents, synthetic oil, alkali, thread-lock fluid or similar chemicals; choose the metal bowl if in doubt.

Typical Applications in Oman & the GCC

In the hot, humid coastal air of Muscat, Sohar, Duqm and the wider GCC, compressors carry a large load of oil and water aerosol. The AFM30-03 class of mist separator is used ahead of paint and powder-coating guns, pneumatic instrumentation in oil & gas and water treatment plants, packaging and bottling lines, and as the pre-filter for an AFD micro mist separator where cleaner air is needed.

Why Source from Seven Star LLC

Seven Star LLC supplies SMC air preparation equipment across Oman and the GCC. Send us the legacy code from the name plate and request a quote; our team can help confirm the correct ordering code for the current -D successor and its replacement elements.