Threaded flange refers to a flange that is connected to the pipe by threads. When designing, it can be treated as a loose flange. The advantage is that welding is not required, and the additional torque generated on the cylinder or pipe when the flange is deformed is very small. The disadvantage is that the flange is thick and the cost is high. It is suitable for the connection of high-pressure pipelines.

Threaded flanges can be made of a variety of materials, including but not limited to carbon steel, alloy steel, stainless steel, etc.

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The size standard of threaded flanges covers a range from small size DN15 to large size DN300. This standard is suitable for a variety of application scenarios, including but not limited to petrochemical, water management, etc.

Threaded flange is a non-welded flange that has its inner hole processed into pipe threads and is connected to a threaded pipe. Compared with flat welding flanges or butt welding flanges, threaded flanges are easy to install and maintain, and can be used on pipelines where welding is not allowed on site. Alloy steel flanges have sufficient strength, but are not easy to weld, or have poor welding performance, so threaded flanges can also be selected. However, when the pipeline temperature changes sharply or the temperature is higher than 260℃ and lower than -45℃, it is recommended not to use threaded flanges to avoid leakage.

The materials of threaded flanges can be varied, including but not limited to carbon steel, alloy steel, stainless steel, etc. The selection of these materials depends on the specific application scenarios and requirements to ensure the performance and durability of the flanges. For example, carbon steel is a common metal material with good plasticity and strength, suitable for most general applications. Alloy steel improves its mechanical properties by adding other elements to meet specific working conditions. Stainless steel is widely used in environments that need to resist chemical corrosion due to its corrosion resistance. In addition, flange pipe fittings can be cast, threaded or welded, and the implementation standards include national standards GB/T17185-1997, GB/T12459-2005, GB/T13401-2005 and other standards.

The models and specifications of threaded flanges include double-head threaded flanges, external threaded flanges, internal threaded flanges, double-head threaded flanges, safety valve threaded flanges, spherical threaded flanges, needle threaded flanges, etc. These models can meet the needs of different applications. Threaded flanges are generally composed of a butt surface, an outer edge ring, and a thread. The butt surface is used to accommodate the threaded end of the pipe fitting, the outer edge ring is used to accommodate the pipe fitting, and the thread is used to join the flange and the pipe fitting together. Common thread specifications include NPT, G, BSP, BSPT, etc. Each thread specification has its specific parameter requirements, such as thread shape, pitch, bolt diameter, etc. NPT is the American National Pipe Thread Specification, G is the German National Pipe Thread Specification, BSP is the British Standard Thread Specification, and BSPT is the British Standard Conical Thread Specification. These specifications are widely used in different countries and regions, ensuring the versatility and interchangeability of threaded flanges.

The instructions for the use of threaded flanges mainly include their installation methods, precautions and applicable environments. ‌

1. Installation method‌: The installation of threaded flanges mainly depends on threaded connection methods, not welding. During installation, the hole in the middle of the flange needs to be processed into a pipe thread, and then the threaded flange is used in conjunction with the threaded pipe. During the installation process, wrap hemp and apply lead oil on the processed threaded pipe, and tighten the threaded flange. This installation method allows the threaded flange to be disassembled and tightened, which is more convenient for cleaning and maintenance of the machine. ‌

‌2. Precautions‌: When using threaded flanges, it is necessary to note that the sizes and specifications of threaded flanges required for different machine installations and different specifications of facilities are different. Therefore, in order to unify standards, the country has set standard sizes for threaded flanges. In addition, the use of threaded flanges requires threaded pipes, and in order to meet the size of threaded flanges, threaded pipes also have a corresponding wide range of specifications. The materials used to make these threaded pipes are generally the same as those of threaded flanges to achieve consistent quality and complete equipment. At present, threaded flanges and threaded pipes are basically made of steel materials, because steel materials have strong pressure resistance, are not easy to break during installation, and have better corrosion resistance than other materials.

‌3. Applicable environment‌: Although threaded flanges are convenient for cleaning and maintenance of machines, they are not suitable for use in all cases. Since threaded pipes are strongly affected by the environment, the temperature fluctuations in threaded pipes are relatively large. Therefore, it is better to use welded flanges in environments above 20 degrees Celsius or below -40 degrees.

In summary, the correct use of threaded flanges requires attention to their installation methods, compliance with national standard sizes, use with appropriate threaded pipes, and consideration of their applicable environments to ensure the effective performance of their sealing effects.

The technical parameters of threaded flanges include nominal diameter, working pressure, materials and uses. ‌

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Nominal diameter‌: The nominal diameter range of threaded flanges is DN8~DN100.

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Working pressure‌: The working pressure range of threaded flanges is 1.0~2.5MPa.

‌Material‌: Common materials for threaded flanges include stainless steel, carbon steel, and alloy steel.

‌Use‌: Threaded flanges are suitable for threaded locking and sealing of industrial and civil pipes such as fire protection, gas, hot and cold water, air conditioning, air compressor pipes, oil pipes, instruments, and hydraulic pipes.

These technical parameters provide specific guidance for the use of threaded flanges, ensuring their safety and reliability in different application scenarios.