For steam pipes, high temperature pipes, low temperature pipes and pipes with anti-scalding and anti-freezing requirements, it is necessary to cover the outside of the pipes with thermal insulation materials to prevent the loss of heat (cold) in the pipes or freezing. For some liquid pipelines with high freezing point, heating and insulation are also required to prevent the liquid from being too viscous or solidifying and affecting the transportation. Commonly used insulation materials are cement perlite, glass wool, rock wool and asbestos diatomite.
