Characteristics and construction requirements of foam insulation pipe

The foam insulation pipe is corrosion-resistant, has good thermal insulation performance and has a long service life. Compared with other pipe insulation materials, the insulation effect of foam insulation pipe is increased by 4-9 times. Let's talk about the characteristics and construction requirements of foam insulation pipes:

  The water absorption rate of the foam insulation pipe is very low, about 0.2 kg/square meter. The reason for the low water absorption of the foam insulation pipe is that the closed cell rate of the polyurethane foam is as high as 92%. Low thermal conductivity, low water absorption, high density polyethylene or fiberglass repair shell, good insulation, waterproof exterior. The polyurethane rigid foam insulation layer of the foam insulation pipe is closely combined with the outer layer of the steel pipe, which can prevent air and water from entering the outer layer of the steel pipe, so as to achieve the effect of anti-corrosion.

       The main function of the foam insulation pipe is to reduce the heat loss of the heating medium during the transportation process, save fuel, maintain the heating quality, and meet the needs of users. The use of prefabricated direct-buried thermal insulation cotton pipes can reduce the length of heating pipes and accessories, thereby reducing engineering costs. In addition, the foam insulation pipe can also reduce the heat loss of the insulation pipe to the surrounding environment, because the insulation pipe is insulated. The application of foam insulation pipe can also prevent the surface temperature of the pipe from being too high and scalding maintenance personnel.

      In order to prevent the corrosion of the foam insulation pipe, the surface of the pipe should be coated with anti-rust material first. The thickness of the insulation layer is determined by the technical and economic comparison. The protective layer is usually coated with asbestos cement or asphalt glass cloth and a metal casing. If necessary, waterproof measures should be taken outside the protective layer. The outer surface of the protective layer should be neat, smooth, beautiful, and in harmony with the surrounding environment, and sometimes a layer of color paint should be applied to distinguish pipes for different purposes.

       During the construction of the foam insulation pipe, the groove should be flat to keep the bottom of the groove dry. It is required to have a fine sand cushion of about 200 mm, and at least the sides and upper part of the insulation pipe should be covered with about 200 mm of fine sand. Its purpose is to prevent hard objects from damaging the insulating jacket, and to use the fluidity of the sand to adequately fill the gaps around the pipes to ensure adequate friction.

       After the pipeline installation of the foam insulation pipe is completed, a water pressure test of 1.5 times the working pressure should be carried out, and the interface foaming treatment can be carried out only after the water pressure test is qualified. It must be ensured that the outer surface of the interface steel pipe, the insulating end surfaces on both sides and the outer surface of the shell of the lap joint are completely removed from water, oil, impurities and end surface protective layers. When the interface adopts polyurethane foam, the ambient temperature shall not be lower than 10℃.