A flange is a cast or forged steel product used to connect a pipe with another mechanical device, forged steel flanges are preferred due to their intrinsic strength and durability

Flanges are available in multiple types, the standard ones are the welding neck, blind, socket weld, lap joint, threaded, etc.). There are also some special types of flanges, like the swivel flanges, the expander/reducer flanges, the Nipoflange / Weldoflange, and the orifice flanges.

As a general rule, welding neck, slip-on, and socket weld flanges are used for high-pressure applications that require long-lasting flanged joints. Threaded flanges can be used with a lower pressure piping system, and if vibrations are not present.

Lap joint flanges are used in connection with stub ends either to facilitate the alignment of the bolts of the two mating flanges, or to reduce the cost of noble materials in high-grade flanged joints.
Example, in an Inconel piping system, the stub end connected to the pipe may be in Inconel, whereas the lap joint flange can be of a lower grade, thus saving the overall weight of the expensive Inconel material.

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Material Grade

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