Introduction to Flanged Socket Welding Fittings

Slip-on Flange (Full Name: Slip-on Weld Neck Steel Pipe Flange); Abbreviated as "so" Flange; A type within the Weld Neck Flange series.

A necked flat welding flange is similar to a flat welding flange, which connects pipes and fittings to equipment or pipelines by inserting them into the flange and securing them with angular welds.

The difference between flanged weld neck and socket weld neck flanges lies in the method of welding. The flanged weld neck involves inserting steel pipes and fittings into the flange bore and welding them, whereas the socket weld neck aligns the neck with the steel pipe and fittings for welding. A more straightforward distinction is that the neck of the flanged weld neck is shorter, and the neck of the socket weld neck is taller.

Features of Neck Flanged Welding Flange

Aesthetically pleasing, with a smooth and flat surface, ***resistant to acid and alkali, ***corrosion-proof, and strong in texture and performance.

Waist flange with neck is easy to maintain shape, boasts excellent sealing properties, and has wide applications.

Socket welding flanges save space and reduce weight, but more importantly, they ensure no leakage at the joint and offer excellent sealing properties.

Specification Model

DN15-DN1000

Pressure Grade

PN Series: PN6 to PN100

Class Series: Class150 to Class1500

Sealing Surface Type

Rounded Face (RF)

Full Flat (FF)

Concave-convex (MFM)

Concave FM)

Convex M)

Tenon and groove face (TG)

The concave-convex surface (MFM) is for matching use.

Weld Neck Flange Material

Carbon Steel Flanges: ASTM A105, 20#, Q235, 16Mn, ASTM A350 LF1, LF2 CL1/CL2, LF3 CL1/CL2, ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65, F70

Stainless Steel Flanges: ASTM A182 F304, 304L, F316, 316L, 1Cr18Ni9Ti, 0Cr18Ni9Ti, 321, 18-8

Alloy Steel Flanges: ASTM A182 F1, F5a, F9, F11, F12, F22, F91, A182F12, A182F11, 16MnR, Cr5Mo, 12Cr1MoV, 15CrMo, 12Cr2Mo1, A335P22, St45.8/Ⅲ

Standard of Execution

China National Standard: GB/T 9116-2010 Flanged Steel Pipe Fittings with Neck Welding

China National Standard for Chemical Industry: HG/T20592-20635-2009, PN series (European system), Class series (North American system) as per HG/T20592-20635-2009.

Connection Type

Single-sided welding, double-sided nut connection;

In simple terms, it involves inserting the pipe into the inside diameter of the neck butt-welding flange, welding it in place, and then securing both sides with bolts and nuts.

Production Process

Pure forging, semi-finished forging (second choice) are suitable for necked slip-on flanges and neck welding flanges.

AOx furnace blanking, full forging or finished forging cutting shaping, high-precision CNC lathe turning, CNC radial arm drill boring.

Advantages and Disadvantages of Socket Weld Flanges

Advantages: The necked flat welding flange is also a type of flat welding flange, as the short neck enhances the flange's strength and improves its load-bearing capacity, making it suitable for use on piping systems with higher pressure.

Drawbacks: More expensive than plate-type flat welding flanges; more prone to磕碰 during transportation due to its shape characteristics.

Procurement Recommendations

1: We recommend purchasing from a certified neck weld flat flange manufacturer with a substantial production scale.

2: manufacturers of flanges need to provide material inspection reports and other relevant documents for necked butt-welding flanges.

3:颈平焊法兰 must have corresponding specification model stamping and marking.