First, a common natural gas pipeline
1, galvanized pipe: the galvanized layer is easy to wear off, and the pipe wall is corroded and blocked, resulting in scale and bacteria. Not only the actual service life is less than 10 years, but also hidden diseases in daily life.
2. Composite pipe: Composite pipe is the pipe that replaces the second upsurge of galvanized steel pipe. According to the position of the metal pipe, there are three types of composite pipe:
A) Metal pipes are on the outside, such as plastic-lined steel pipes, plastic-coated steel pipes and aluminum alloy plastic-lined pipes;
B) Metal pipes are on the inside, such as plastic-coated copper pipes and plastic-coated stainless steel pipes;
C) Metal pipes are in the middle, such as aluminum-plastic composite pipes, steel skeleton plastic composite pipes, plastic-coated composite pipes inside and outside, etc.
3. Copper pipe: from hot water pipe to cold water pipe; From high-standard buildings to medium-standard buildings, in recent years, due to people's concern about the "blue water" phenomenon in the futures market and malicious speculation, the further application of copper pipes has been affected to some extent. However, there are many limitations in the application environment of cast iron pipes in building water supply pipes, and people focus on stainless steel pipes [1].
4. Stainless steel pipe: Stainless steel is a pollution-free metal material with excellent physical properties and high cost performance, once and for all. Stainless steel is not only used in food industry, including beverage, dairy products, brewing, pharmaceutical industry, tableware and cookware, but also widely used in medical human bodies with high requirements on material safety and cleanliness, such as various stents, artificial joints and internal steel nails.
Second, the gas pipeline fault and treatment
1, because the gas pipeline is exposed to the outside all the year round, it is easily affected by the structural stress caused by atmospheric corrosion and bad weather, and many parts of the gas pipeline are made of rubber, which is easily affected by factors such as corrosion and aging of chemical media, resulting in leakage of some parts, which has great security risks. At present, there are three leakage points in industrial gas pipeline: 1, gas metal pipeline leakage, gas pipeline expansion joint leakage (expansion joint is a flexible structure arranged on container shell or pipeline to compensate additional stress caused by temperature difference and mechanical vibration of gas pipeline) and gas pipeline soft connection leakage.
2. The traditional method to solve the safety hazard of gas pipeline is mainly to stop using and replace accessories, but it will cause great waste of resources and affect production. At present, polymer composite materials are widely used in foreign countries for on-site repair. At present, the more mature system is Fuji Blue series. Because of its superior adhesion and excellent compressive strength, polymer materials can avoid disassembly and shutdown, and have advantages over traditional repair methods, and are gradually recognized in China to control gas pipeline leakage.