Comparative Analysis of Temperature Resistance of Different Flange Materials

As a key part of pipeline connections, flange material directly affects the running condition of pipe, especially the temperature resistance of pipe. Flanges made of different materials exhibit obvious differences in temperature resistance, mechanical properties and corrosion resistance. The advantages and disadvantages of flange are systematically analyzed and compared according to its physical and chemical properties and its industrial application, which provides reference for engineering design and material selection.
Heat resistance of Carbon Steel Flanges
Carbon steel is one of the most widely used materials in flange because of its low cost and mature manufacturing process. According to the carbon content and alloy elements, the temperature resistance limit of ordinary carbon steel flanges is generally between -29°C and 400°C. Common carbon steel flanges, such as A105, are generally limited to a maximum operating temperature of 425°C. Under high temperature conditions, carbon steel can harden on the surface and soften on the inside, which leads to decrease in strength and oxidation corrosion, which limits the use of carbon steel in high temperature environment.
It is important to note that as temperature increases, the thermal expansion coefficient of carbon steel increases, which may lead to a decrease in the sealing performance of the flange joint, leading to the risk of leakage. Carbon steel flanges have excellent welding performance and are suitable for equipment and piping systems with moderate temperature and not particularly high pressure.
Heat resistance of Alloy Steel Flanges
Alloy flange can improve its heat and corrosion resistance resistance by adding molybdenum, chromium and nickel. Typical alloy steel, such as 12Cr1MoVG and 15CrMo, can withstand temperatures of 500-600°C. Some special high alloy materials, such as the Incoloy series, can even exceed 700°C.
Alloy steel flanges is suitable for high temperature and high pressure environment. Widely used in petrochemicals, power plants, boilers and other industries. It has great resistance to oxidation and mechanical fatigue, which means it can make the equipment last longer. But they are expensive and hard to make because they need special welding materials and tight process control.
Heat resistance of Stainless Steel Flanges
Stainless steels is classified according to austenitic, ferritic, and duplex structures, each of which has its own unique heat resistance characteristics. . Austenitic stainless steels (e.g. 304 and 316) contains nickel and is temperature resistance. Its operating temperature ranges are typically -196°C and 870°C. However, continuous operating temperatures are usually limited to less than 800°C; intergranular corrosion and other problems can occur above 850°C.
Compared to Ferritic and duplex stainless steels are slightly less temperature resistance, with temperature limits between 600 °C and 700 ° C. Stainless steel flanges not only resists high temperature, but also has excellent corrosion resistance and antioxidant ability, suitable for acid, salt and high temperature steam environment. However, intergranular corrosion and stress corrosion cracking are more likely to occur at high temperature, so the stability of the material must be considered when designing.
Heat resistance of copper alloy flange
Copper and copper alloy flanges are mainly used in low-pressure systems that require high corrosion resistance, such as water treatment and ship equipment. They are usually between -50°C and 350°C. Over 400 ℃, the mechanical strength of copper alloy decreases significantly, oxidation intensifies, and sealing performance decreases.
Copper alloy flanges has the advantages good thermal conductivity, easy to achieve rapid temperature equalization quickly, and suitable for rapid cooling and heating conditions. However, their high temperature tolerance is limited, not suitable for high temperature and high pressure environment. This is the limitation of copper alloy flange applications.
Thermal Resistance of Engineering Plastic Flanges
PTFE (PTFE), polypropylene (PP) and other Engineering plastic flanges are mainly used in chemically corrosive environments and generally have a temperature resistance between -50°C and 120°C. PTFE flanges can withstand high temperature up to 260°C, but long-term use is generally limited to 200°C. Excessively high temperatures can lead to softening, deformation or thermal cracking.
Plastic flanges have the advantages of excellent corrosion resistance, light weight and easy installation, but their mechanical strength and temperature resistance are much lower than metal flanges, so they are not suitable for high-pressure or high-temperature environments. Their applications are concentrated in low-temperature, low-pressure and non-mechanical load environments.