Standard and Custom Blower Materials

Spencer’s standard materials of construction include carbon steel with aluminum impellers and cast iron with cast aluminum impellers.

Standard coatings are epoxy primer for all stationary interior and external surfaces, and a urethane exterior topcoat.

Materials of Construction

• Carbon steel
• Cast iron
• Aluminum
• 300 Series stainless steel
• 400 Series stainless steel
• Carpenter® 20 stainless steel
• AR steel
• FE 255®
• Cor-Ten®
• Monel 400
• Hastelloy C22
• Hastelloy C276
• Inconel 625
• AL6XN
• Titanium
• Brass / Bronze

Special Coatings

• Teflon®
• Ryton®
• Anodizing
• Electroless nickel
• Heresite® or Bisonite® baked phenolic
• Plastisol® PVC
• Galvanizing
• Special paint (e.g., epoxy, enamel, polyurethane)

Custom Metals and Coatings

Scores of other metals and coatings are available for customized performance. Spencer engineers have unparalleled experience in selecting and applying unusual metals and coatings, because they deal every day with the most difficult applications in the world.

One common approach is to combine standard and custom materials. Specialized alloys can be used for components exposed to corrosive gases; less expensive materials can be used for all unwetted parts. The result is a blower that has special protection where it is needed and economy where it is not.

Beneficial Properties

Custom metals and coatings offer specific properties, such as:

• Corrosion resistance
• Abrasion resistance
• Spark-resistant operation
• Non-stick (anti-fouling) performance
• High or low temperature resistance

Which are better, Special Metals or Coatings?

Coatings are often used for their anti-fouling properties or for passivation of metal surfaces. But in many other instances, coatings and special materials are simply two ways of reaching the same result. Selecting one over the other depends on your preferences and your circumstances. You need to examine economic factors such as the cost of coatings vs. exotic alloys, and life cycle considerations (e.g., are you looking for 40,000 or 4,000,000 duty cycles?).

Sometimes it makes sense to use “disposable” coated blowers and replace them periodically. Or, in a critical process, it might be vital to avoid downtime by using long-life alloys.

In some cases, a special coating must be accompanied by a special material (e.g., high temperature coatings and high temperature steels must be used together) to deliver consistent results.

Note that coatings can be applied to counter internal or external conditions. A special exterior paint might be used in humid environments to prevent rust, for example.

Maybe a corrosion allowance would provide all the protection you need

If corrosion is the application problem and its rate is slow, predictable and acceptable, you may be able to avoid using either coatings or expensive special metals. A corrosion allowance involves a blower casing metal that is thicker than usual to accommodate corrosion. Thus, a thick section of 304SS might be used instead of a much more costly casing of Hastelloy.

The thickness of the corrosion allowance can be specified to reach a desired service life for the blower.