Asbestos gallery: Asbestos thermal insulation

Asbestos Thermal Insulation

Location/use:

Thermal insulation of pipes, boilers, pressure vessels, calorifiers, etc.

Asbestos content and type / date last used:

All types of asbestos have been used. Crocidolite (blue) asbestos was used in lagging until 1970. Amosite (brown) asbestos was phased out by the manufacturers during the 1970s. Asbestos content varies from 6%-85%. Various ad hoc mixtures were hand-applied on joints, bends and pipe runs. Pre-formed sections were widely used – for example, 85% magnesia contained 15% amosite (brown) asbestos. ‘Caposil’ calcium silicate slabs and blocks contained 8-30% amosite (brown) asbestos, while ‘Caposite’ sections contained 85% amosite (brown) asbestos. Thermal insulation asbestos blankets, felts, papers, tapes and ropes were usually made of 100% chrysotile (white) asbestos.

Ease of fibre release and product names:

The ease of fibre release often depends on the type of lagging used, and the surface treatment. It is often encapsulated with calico and painted (for example, PVA, EVA, Latex, bitumen or propriety polymer emulsions or PVC, Neoprene solutions). ‘Decadex’ finish is a propriety polymer emulsion. A harder chemical/weather resistant finish is known as ‘Bulldog’.