1. Whether the heat insulation layer of black jacket insulation pipe is eccentric, that is, polyurethane insulation layer is different from steel pipe, and the insulation thickness is uneven, and serious people will be damaged by external plastic softening.

2. The use of black jacket insulation pipe is easy to be damaged in the process of transportation and installation. After sinking, the ground depth is insufficient, or the upper soil and road are soft, and the loading vehicle is trampled.

3. In the process of pipeline installation, the welding of the two pipes can't penetrate tightly, or they can't work normally in the process of "filling", and the external sewage can't penetrate the insulation layer.

4. If it is often found that the material of jacket pipe (such as waste recycling plastic) is used, the extruded plastic pipe can not be fully plasticized, and the external pipe will deteriorate. Polyurethane insulation pipe has low density and low strength, which is damaged in the process of treatment. The glass acid in the system is too high, and corrosion occurs on the outer wall of steel pipe.

Polyurethane black jacket thermal insulation pipe is a kind of direct buried insulation pipe with good thermal insulation performance, safety and reliability, and low engineering cost. It can effectively solve the problems of heat preservation, sliding lubrication and waterproof of pipe ends of the prefabricated directly buried insulation pipe for 130c - 600C high temperature heat transmission in urban central heating. High temperature prefabricated directly buried insulation pipe not only has the advanced technology and practical performance that traditional trench and overhead laying pipeline can't match, but also has significant social and economic benefits, which is also a powerful measure of heating and energy saving. The high temperature prefabricated directly buried insulation pipe is tightly adhered to the outer skin of the steel pipe due to the rigid polyurethane foam insulation layer, and the air and water infiltration are separated from the insulation layer, which can play a good anticorrosive role. At the same time, its foam cells are closed, water absorption is very small. The high density shell of polyurethane insulation pipe and the glass fiber reinforced plastic shell of polyurethane insulation pipe have good anticorrosion, insulation and mechanical properties.

PU foam insulation foam strength is small, soft foam phenomenon is caused by imbalance between black and white ratio, appropriate increase the proportion of graphite can (1: 1-1.05). Please note that the proportion of black material should not be too large. Otherwise, the foam crisp will also affect the performance of the foam. Polyurethane black jacket incubator prefabrication incubator is a direct selling incubator with good heat preservation performance, safety and reliability, and low engineering cost.