Removable Insulation Blankets – An Overview

Removable Insulation Blankets are used to insulate engine parts, exhaust piping and components,and industrial process piping and machinery. In particular,applications which use diesel engines, such as power generation, off highway & on-highway vehicles, and marine often require insulation blankets to manage the heat that these engines generate.

Stand-By Power, Dawoo P222LE Engine	Mining Vehicle	Co-Generation Waste Recovery, CAT 3516 Engine

How Are They Constructed?

Removable insulation blankets are typically constructed in 3 layers.* The table and photos below illustrate the construction and materials used in a standard removable insulation blanket.

Insulation Blanket Construction

Layers	Material	Temperature Limit	Function
Outer	Silicone Impregnated Fiberglass	Grey: 500° F (260° C) Red: 600° F (316° C)	Protective Cover
	Aluminized Fiberglass	500° F (260° C) Coating 1000° F (538° C) Fabric **
Middle	Fiberglass	Firwin 1200: 1200° F (649° C)	Insulation Media
	CMS Wool	Firwin 1800: 1800° F (982° C)
Inner	Stainless Steel Mesh***	Firwin 304SS: 1200° F (649° C)	Contains Insulation Media
		Firwin 309SS: 1800° F (982° C)

* Certain applications require alternative construction methods – i.e. an extra layer may be added, as in the case of sound or fluid barriers.
** Aluminum coating may separate from fiberglass fabric at 500°F+, but fabric maintains good strength until 1000°F.
***The stainless steel inner liner may replaced by a fiber-containing material in cases where fiber containment is a requirement.

Heat Performance of Insulation Media

The chart below details the heat performance one can expect from removable insulation blankets. The chart shows what the temperature of the outer surface of the insulation blanket would be (touch temperature) at various temperatures of the part being insulated (hot surface). The chart also outlines at what hot surface temperature the insulation blankets reach the "safe touch limit" (as per UL 2200). For firwin 1200, the "safe touch limit" is reached at just over 700°F, while for firwin 1800, this limit is reached at 800°F.

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Firwin FAQ - Proper Care of Removable Insulation Blankets

Here are six easy tips to help you ensure the proper performance and longevity of your insulation blankets:

1. The fastening system is more than suitable to hold the blankets in place. Care must be taken not to use brute strength when installing blankets.
2. For the best service, blankets should be kept clean.
3. Any chemicals which will cause deterioration of the aluminum or silicone coatings should be removed and cleaned off.
4. Should the blanket or insulation matt become saturated with oil, their natural "non-combustible" characteristics will no longer be effective and the blanket should be replaced.
5. Like all engine parts, blankets should be regularly inspected.
6. Care must be taken not to cut or damage the outer protective cover fabrics with sharp instruments.

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