Perlite is the waterproof heat insulation material that is asbestos-free and of high intensity with high quality perlite particles as the main material and made by cohering inorganic bond and reinforced fiber(It is a non-asbestos, high performance and water repellent insulating material that is composed of high-quality expanded perlite particles, bonded with inorganic binder and reinforcing fiber);it highest use temperature is 650℃,with super-low heat conductivity coefficient and super-low chloride ion content, it has very good protection on peripheral steel pipes; being prefabricated to shape up and resistant to deform, it has the same service life of buildings. its overall water repellency is nice and it integrates the function in terms of heat reservation, thermal insulation and water resistance, saving great amount of construction and maintenance fund. It is not only able to have heat reservation function on petrochemical industry pipelines and equipment, but also has very nice fire prevention and radiation resistance, and the manufacturer is the only in domestic that has reached the US ASTMC610 standard.