WN neck welded flange

Welding flange is a common type of pipe fitting, also known as WN neck welding flange. It refers to a flange with a neck and a circular pipe transition, which is welded to the pipe. Welding flanges are not easily deformed, have good sealing, are widely used, have corresponding requirements for rigidity and elasticity, and reasonable welding thinning transition. The distance between the weld and the joint surface is large, and the joint surface is protected from welding temperature deformation. The sealing surface of butt welded flanges is generally convex (RF), concave convex (concave FM convex M), and mortise and tenon groove are not commonly used. Docking welding flanges are suitable for pipelines with significant pressure or temperature fluctuations, as well as pipelines with high, high, and low temperatures. They are also used for pipelines transporting petroleum, chemicals, flammable, and explosive media. The welding method used for connecting flanges and pipelines through butt welding is butt welding, and the weld seam is similar to the welding between pipelines. Generally, for small pipe diameters, argon arc welding is used as the base and manual welding is used for the cover, while for large pipe diameters, double-sided welding is used.

A flange, also known as a flange, is a component that connects pipes to each other. There are holes on the flange, and bolts tightly connect the two flanges. Flange connection refers to a detachable connection composed of flanges, gaskets, and bolts that are connected to each other as a combined sealing structure. Pipeline flange refers to the flange used for piping in pipeline devices, and used on equipment refers to the inlet and outlet flange of the equipment. Seal the flanges with gaskets. Flanges are divided into threaded flanges and welded flanges.

WN neck butt welding flanges can be divided into carbon steel according to their manufacturing materials: (20 #, A3, Q235, Q235A, Q235B, 20G, 16Mn, Q345, Q345R, 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.);

Common types and codes of flanges: 1. PL plate flat welding flange, 2. SO with neck flat welding flange, 3. WN with neck flat welding flange, 4. SW socket welding flange, 5. Th threaded flange, 6. BL flange cover, 7. Eight character blind plate, 8. PJ/SE with neck flat welding ring loose flange, 9. PJ/PR flat welding ring loose flange, 10. reducing flange, 11. stainless steel flange, 12. pressure vessel flange, 13. American standard flat welding flange, 14. American standard SO with neck flat welding flange, 15. American standard WN with neck flat welding flange

Common sealing surface form codes for flanges: convex surface RF, concave surface FM, convex surface M, tenon surface T, groove surface G, full plane FF, ring connection surface RJ

Common execution standards for flanges: The current flange standards in China are divided into two systems, namely the PN series (European system) and the Class series (American system). The pressure markings specified in this standard are divided into PN markings and Class markings. The PN label has 12 pressure levels, namely: PN2.5; PN6; PN10; PN16; PN25; PN40; PN63; PN100; PN160; PN250; PN320; PN400。 The Class label has 6 pressure levels, namely: Class 150; Class 300; Class 600; Class 900; Class1500; Class 2500。 The implementation standards include GB series (national standards), JB series (mechanical department), HG series (chemical department), ASME B16.5 (American standard), BS4504 (British standard), DIN (German standard), JIS (Japanese standard).

National standards: GB/T9112-2010, GB/T9119-2010, GB/T9116-2010, GB/T9115-2010

Standard of the Ministry of Chemical Industry: HG/T20592-2009、HG/T20615-2009、HG5010-52～HG5028-58、HGJ44-91～HGJ65-91、HG20592-97

American standards: ASME B16.5, ASME B16.47

Mechanical Department Standards: JB81-59~JB86-59, JB/T79-94~JB/T86-94, JB/T74-1994

Pressure vessel standards: NB/T47020-2012 、NB/T47021-2012(JB/T4701)、NB/T47022-2012(JB/T4702)、NB/T47023-2012(JB/T4703)、NB/T47024-2012(JB/T4704)