Construction of Polyurethane Thermal Insulation Pipe
Thermal insulation of polyurethane direct buried thermal insulation pipeline is divided into three layers from inside to outside. The first layer is composed of seamless pipe (GB8163-87), spiral welded pipe (GB9711-88; SY/T5038-92) and straight welded pipe (GB3092-93) according to design and customer requirements. After treatment by advanced shot peening rust removal process, the steel tube rust removal grade can reach Sa2 level in GB8923-1988 specification, and the surface roughness can reach R=12.5 micron in GB6060.5-88 specification.
The second layer of pipeline thermal insulation: polyurethane thermal insulation layer is made by injecting rigid polyurethane foam plastics into the cavity formed by the high-pressure foaming machine between the outer protective layer of the pipeline. That is commonly known as "tube-in-tube foaming process". Its function is waterproof, heat preservation and self-weight support of heat network. The rigid polyurethane foam is chosen as insulation layer when the temperature of delivery medium is -50 ~120 ~C.
The third layer of pipeline insulation: high density polyethylene (HDPE) maintenance layer is prefabricated into black (yellow) plastic pipes with a certain wall thickness. Its function is to protect polyurethane insulation layer from damage by mechanical hard objects, and the second is anti-corrosion and waterproof. Thermal insulation of polyurethane direct buried thermal insulation pipeline: It is suitable for thermal insulation and cooling engineering of various mediums in the range of - 50 ~150 C. It is widely used in urban central heating, heating room, cold storage, coal mine, petroleum port, chemical industry and other industries of thermal insulation and cooling engineering. Pipeline insulation disadvantage characteristic 1 reduces project cost. According to the calculation of relevant departments, the cost of heating pipeline can be reduced by 25% (using FRP as maintenance layer) and 10% (using high density polyethylene as maintenance layer) under normal conditions. 2. Low heat loss and waste of power. Its thermal conductivity is: lambda=0.013-0.03kcal/m.h.oC, which is much lower than other commonly used pipeline heat preservation data, and the heat preservation effect is improved by 4-9 times. Moreover, its water absorption rate is very low.
About 0.2 kg/m2. The reason for low water absorption is that the polyurethane foam has a closed porosity of about 92%. Low thermal conductivity and low water absorption, together with insulation layer and waterproof high density polyethylene or fiberglass reinforced plastic maintenance shell, have changed the traditional trench laying of heating pipeline "wearing wet cotton jacket", greatly increased the overall heat loss of heating pipeline, heat loss of heating network is 2%, less than the international norms of 10%. 3. Anti-corrosion, good insulation function and long service life. Because the polyurethane rigid foam insulation layer is tightly bonded to the outer skin of the steel pipe, the infiltration of air and water can be isolated, and good anticorrosion effect can be achieved. At the same time, its foaming holes are closed and its water absorption is very small. High density polyethylene shell and FRP shell have good anti-corrosion, insulation and mechanical functions. Therefore, the outer skin of the task steel pipe is very comfortable to the corrosion of the outside air and water. As long as the external water quality of the pipeline is disposed well, the service life can reach more than 50 years, which is 3-4 times longer than that of traditional trench laying and overhead laying.
This article is provided by Shandong Hipper Pipe Technology Development Co., Ltd. https://www.sdhpgy.com. We would like to know more about polyurethane insulation pipe manufacturers. Welcome to pay attention to us. Thank you!
