Types and standards of flanges

　　Flange Types and Standards

　　Flanges, also called flange plates or flanges, are manufactured through four processes: forging, casting, cutting, and rolling. Die forging is the most common method. Die forging, also known as mold forging, involves placing a heated blank into a die fixed on forging equipment and shaping it.

　　I. Flange Classification:

　　Common flange types include: plate flat-face flanges, neck flat-face flanges, neck butt-welding flanges, socket-welding flanges, threaded flanges, loose-fitting flanges, and flange covers.

　　Common size range: 1/2” (DN15) - 24” (DN600).

　　European standard nominal pressure is expressed in PN, including nine grades: PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, and PN160. The nominal pressure rating in American Standard (ASM) is indicated by CLASS, including six levels: CLASS 150, CLASS 300, CLASS 600, CLASS 900, CLASS 1500, and CLASS 2500.

　　Plate-face slip-on flange (PL): Easy to source materials, simple to manufacture, low cost, and widely used.

　　Sealing face type: Flat face (FF) and raised face (RF).

　　Slip-on flange with neck (SO): A flange for connecting steel pipes, fittings, etc., to equipment or pipelines through a fillet weld.

　　Sealing face form: Raised face (RF), concave face (FM), male face (M), tongue and groove (T), grooved face (G), flat face (FF).

　　Welding neck flange (WN): Used for butt welding of flanges to pipes; it has a reasonable structure, high strength and rigidity, and reliable sealing performance.

　　Sealing face types include: flat face (FF), raised face (RF), male face (M), female face (FM), tongue and groove (T), grooved face (G), and ring joint face (RJ).

　　Socket weld flange (SW): This refers to a flange where the pipe end is inserted into the flange ring step, and welding is done to the pipe end and the outside. It comes in two types: with neck and without neck.

　　Sealing face types: raised face (RF), male face (MFM), tongue and groove face (TG), and ring joint face (RJ).

　　Threaded flange (TH): This is a non-welded flange where the inner hole of the flange is machined into a pipe thread and used to connect with a threaded pipe. Threaded flanges are easy to install and maintain, and can be used on pipelines where welding is not permitted on site.

　　Loose flange (LAPJ): Generally divided into butt-welded loose flange and flush-welded loose flange.

　　Flange cover (BL): Also known as a blind flange or blind plate. This is a flange without a central hole, used to seal pipe plugs.

　　Sealing faces: Flat face (FF), Raised face (RF), Male face (MFM), Tongue and groove face (TG), Ring joint face (RJ)

　　II. Flange Standards

　　Standards include ASEM B16.5, ASME B16.47, GB/T 9112-GB/T9124, HG 20592-HG20605, HG20615-HG20626, and SH3406.

　　III. Flange Materials

　　Common materials include carbon steel, stainless steel, and alloy steel. ASTM A105; A182 F5, F11, F12, F22, F91, F304/L, 316/L, F904L; A350LF2/LF3, A694 F52, F60, F65.
       Shengtian Group supplies various types of flanges for your selection and can also customize flanges according to drawings. If you have any flange order needs, please feel free to contact us at Email: sale@stpipefitting.cn