Materials we have built fans in — matched to your gas, heat and wear.

Materials of construction (MOC) are the grades a fan's casing, impeller, shaft and wetted parts are made from. On a centrifugal fan they are set by what the airstream carries — its chemistry, moisture and dew point, temperature and dust — and by where the fan sits: a wash-down food hall, a coastal plant, a hot kiln line. The same duty point in clean air and in acid fume needs different metal, and the difference is usually the difference between a fan that lasts and one that is replaced.

We work from the process medium you state: the gas or vapour and its concentration, moisture and dew point, operating and upset temperature, dust loading and abrasiveness, and any wash-down or hygiene regime. Where only the airstream sees the corrosion, we put the alloy where the gas is — airstream-only stainless on a carbon-steel frame — rather than building the whole fan in the costlier grade.

Five things set the grade

What we read off your duty sheet.

• Chemistry and moisture — chlorides, acid fume and a condensing dew point move the wetted parts to SS 316L or Duplex 2205, built to your stated gas analysis.
• Temperature — hot-gas duty up to 500 °C moves hot-side parts to heat-resisting SS 310 or SS 321.
• Dust and abrasion — Hardox wear liners at the scroll, volute throat, outlet and inlet, with hard-faced blade leading edges where the dust calls for it.
• Hygiene and ambient — SS 304 or SS 316L for food, pharma and wash-down duty, and where coastal or chemical-plant air attacks the outside of the fan.
• On the drawing — the grade for every part is written on the GA drawing you approve, before we cut metal.

Carbon and structural steel grades we have built fans in

This allocation is typical practice. The grade for every part of your fan is set by your duty, not by the table.

Stainless and duplex grades we have built fans in

Choosing between 304 and 316? Read SS 304 vs SS 316 for fan construction →

On dust-laden duty — fly ash, cement, clinker, foundry sand, mineral grit — we line the wear zones with Hardox 400, 450, 500 or 600 abrasion-resistant plate: the scroll, the volute throat, the outlet and the inlet. The liners are replaceable, so on abrasive duty the wear surface is the part that is renewed. Blade leading edges are hard-faced where the dust calls for it. Hardox is a wear liner in our builds — the casing and the impeller stay in the structural or stainless grade the duty asks for.

Wear protection: AR plate, hardfacing and ceramic  ·  Dust extraction  ·  Pneumatic conveying  ·  Induced draft  ·  Aftermarket & repair

PP casing and wetted parts, with your choice of SS 316L or FRP-coated impeller — and we state the expected impeller life on your duty, in the offer, and supply the standby.

Where a carbon-steel fan suits the duty, its gas-touched surfaces can carry an acid-resistant FRP coating. Where the chemistry allows a metal, SS 316L or Duplex 2205 on the wetted parts is the alternative, selected to your stated gas analysis and dew point; where neither holds, we step up to a higher alloy against your specification. Bare steel is never left in a saturated acid airstream.

Surface coating & plating  ·  Corrosive gas exhaust  ·  Acid dew point and ID fan corrosion  ·  Executed plating-line fans

For flammable vapour and combustible dust, spark-resistant construction to AMCA 99 Type A, B or C uses aluminium on the airstream parts, and brass as rub rings, linings and plates. Which type applies is a consequence of your area classification and the material in the airstream, so we build to the type your specification states rather than offering one as standard.

Spark-resistant fans: AMCA Type A, B and C  ·  ATEX and paint-booth exhaust

Carbon-steel fans are blast-cleaned to Sa 2½ and finished in an epoxy or PU paint system, with the dry-film thickness checked before dispatch. Where your specification names its own system, we build to that instead and record it on the drawing.

• Impeller diameters up to 3,000 mm, cut, formed, welded and balanced in our own plant.
• Machining is done by approved suppliers, to our drawing and our inspection.
• Ultrasonic and radiographic testing of welds is done through partner laboratories when your specification calls for it.
• Where a refractory lining is part of the build, it is applied as the specification for that duty requires.

Manufacturing & quality profile  ·  Quality & certifications  ·  Testing & certification

• The gas or vapour, and its concentration.
• Operating and upset temperature.
• Moisture content and dew point.
• Dust type, loading and particle size.
• Any wash-down or hygiene regime.
• Site ambient — coastal, chemical plant, outdoor.
• Any grade your specification already names.