Variable diameter elbow

Variable diameter elbow, also known as reducing elbow, is a pipe fitting that connects two pipes of different diameters for turning. It is to use a standard elbow to apply pressure on one side, and use one-on-one stamping equipment to directly deform the elbow blank in the mold and obtain the required diameter

The commonly used elbows are 45 °, 90 °, and 180 °, and other non-standard elbows such as 60 ° can be customized according to project needs. Elbows are a commonly used type of pipe fittings widely used in basic engineering such as chemical, construction, water supply, drainage, petroleum, light and heavy industries, refrigeration, sanitation, plumbing, fire protection, power, aerospace, shipbuilding, etc

The ways of connecting elbows include direct butt welding, flange connection, threaded connection, and socket connection. The production process of elbows can be divided into: welded elbows, stamped elbows, push made elbows, cast elbows, etc

⑴. Elbows are classified by material into carbon steel, stainless steel, alloy steel, special alloy steel, duplex stainless steel, etc; Carbon steel: (20 #, A3, Q235, Q23 excellent, Q235B, 20G, 16Mn, ASTM A234WPB, ASTM A105, etc.); Stainless steel: (304, 304L, 316, 316L, S30408, S30403, S31608, S31603, SUS304, ASTM A403, TP321, TP317L, 347, 0Cr18Ni9, 00Cr19Ni10, 00Cr17Ni14Mo2, 1Cr18Ni9Ti, 06Cr17Ni12Mo2, 022Cr17Ni12Mo2, etc.); Alloy steel: (16MnR, Cr5Mo, 12Cr1MoV, 10CrMo910, 15CrMo, 12Cr2Mo1, A335P22, St45.8/III, A10bB, etc.); Special alloy steel: (TP310S, 904L, Incoloy800, Incoloy825, Incoloy600, Incoloy625, etc.); Dual phase stainless steel: (F51, S31803, S2205, F53, 2507, S32750, F55, 2607, S32760, etc.)

⑵ According to the production method, it can be divided into pushing, pressing, forging, casting, etc

According to manufacturing standards, it can be divided into national standards, electrical standards, ship standards, chemical standards, water standards, American standards, German standards, Japanese standards, Russian standards, etc

⑷ According to its curvature radius, it can be divided into long radius elbows and short radius elbows. A long radius elbow refers to a pipe with a curvature radius equal to 1.5 times the outer diameter of the pipe, i.e. R=1.5D. A short radius elbow refers to a curvature radius equal to the outer diameter of the pipe, i.e. R=1.0D. (D is the diameter of the elbow, R is the radius of curvature)

If classified by pressure level: there are approximately seventeen types, which are the same as the pipe standards in the United States, including Sch5s, Sch10s, Sch10, Sch20, Sch30, Sch40s, STD, Sch40, Sch60, Sch80s, XS; Sch80、SCH100、Sch120、Sch140、Sch160、XXS; The commonly used ones are STD and XS

⑹. According to different shapes and purposes, it can be divided into groove elbows, sleeve elbows, double bearing elbows, flange elbows, reducing elbows, seated elbows, internal and external tooth elbows, stamped elbows, push elbows, socket elbows, butt welded elbows, internal wire elbows, etc

Chinese pipe fittings manufacturing standards:

GB/T12459-2017 Steel butt welded seamless pipe fittings

GB/T13401-2017 Steel butt welded seamless pipe fittings

SH/T340-2012 Steel butt welded seamless pipe fittings

SH/T340-1996 Steel butt welded pipe fittings

SH/T3410-2012 Forged steel socket welded pipe fittings

GB/T10752-1995 Marine steel pipe butt welded joints

GB/T12772-1999 Flexible interface cast iron pipes and fittings for drainage

American pipe fittings manufacturing standards:

ASME/ANSI B16.9 Factory manufacturing Seamless steel pipe fittings for butt welding

ASME/ANSI B16.11 socket welding and threaded forging fittings

ASME/ANSI B16.28 steel butt welding small radius elbows and return bends

ASME/ANSI B16.5 pipe flanges and flange fittings

MSS SP-43 forged stainless steel butt welding fittings

MSS SP-83 socket welding and threaded joints

MSS SP-97 socket welding Integral reinforced pipe socket with threaded and welded ends