The temperature and pressure range for a lined polyurethane steel pipe depends on its manufacturing process and material properties. Generally speaking, the lined polyurethane steel pipe is suitable for conveying medium temperature not higher than 120, occasional peak temperature not higher than 140, and working pressure not more than 25MPa pipe network system.
Specifically, the temperature resistance of a polyurethane-lined steel pipe is mainly determined by the material properties of its insulation layer. Generally speaking, polyurethane foam is used as a thermal insulation material, and its use temperature can reach about 120. In practical application, due to the influence of ambient temperature, medium temperature, working pressure and other factors, the use temperature and pressure range of the lined polyurethane steel pipe may be limited to a certain extent. Therefore, in practical applications, it is necessary to select the appropriate lined polyurethane steel pipe according to the specific use environment and working conditions, and ensure that it can withstand the corresponding temperature and pressure during use.
In addition, it should be noted that the applicable temperature and pressure range of the lined polyurethane steel pipe is not the same, and its application range is affected by many factors such as manufacturing process, material performance, and use environment. Therefore, during use, regular inspection and maintenance should be carried out to find and deal with problems in time to ensure the normal operation and service life of the lined polyurethane steel pipe.
1. Internal anti-corrosion treatment: The lined polyurethane steel pipe needs to be treated with internal anti-corrosion to prevent internal corrosion of the pipeline. At present, the most commonly used is the anti-corrosion of cement mortar fabrics, which is to evenly coat a layer of cement mortar on the inner wall of the steel pipe to protect the pipeline. The anti-corrosion layer in the cement mortar can not only prevent the corrosion and scaling of the inner wall of the pipeline, prolong the service life of the pipeline, but also protect the water quality, maintain or improve the water transmission capacity of the pipeline, and have obvious economic and social benefits.
2. External anti-corrosion treatment: External anti-corrosion treatment is an important means to protect steel pipes from external corrosion. The outer anti-corrosion layer is generally made of petroleum asphalt, epoxy coal asphalt and other materials, which need to be coated with at least two layers, and the total thickness should meet the requirements of relevant specifications and standards. The outer anti-corrosion layer can play a role in isolating the steel pipe from the external environment, and prevent the steel pipe from being affected by oxidation and corrosion.
3. Electrochemical protection: Electrochemical protection is a method that uses electrochemical principles to prevent metal corrosion by changing the electrode potential of metal. Commonly used electrochemical protection methods are cathodic protection and anodic protection. For polyurethane-lined steel pipes, the cathodic protection method is generally used to adjust the electrode potential of the steel pipe to a more negative potential by impressing an external current, so as to prevent the steel pipe from being corroded.
4. Thermal spraying anti-corrosion: Thermal spraying anti-corrosion is a method of heating metal or non-metallic materials to a molten state, and then atomizing them into particles through high-speed air flow, and then spraying them onto the surface of steel pipes to form coatings. Commonly used thermal spraying materials are zinc, aluminum, zinc-aluminum alloy, etc. Thermal spraying anti-corrosion has the advantages of large coating thickness, good anti-corrosion effect and convenient construction.
5. Tape anti-corrosion: Tape anti-corrosion is a method that uses tape material to be wound on the surface of steel pipes to play a role in corrosion prevention. Commonly used tape materials are polyethylene tape, polyvinyl chloride tape, etc. Tape anti-corrosion has the advantages of simple construction and low cost, but the durability is relatively poor, and it needs to be maintained and replaced regularly.