Socket Weld Flange

  • Size Range: DN15-DN80 (1/2″- 3″)
  • Pressure Class: PN20-PN250 (Class 150 – Class 1500)
  • Flange Facing Types: RF, RJ, M, FM, T, G
  • Design Standards: ASME B16.5, JIS B2220, EN 1092-1, HG/T 20592 and other international standards
  • Material Selection: 304 / 316L Stainless Steel, Hastelloy C, Alloy 20, Duplex 2205, Super Duplex 2507, 904L, 310S, Titanium TA2, Carbon Steel 20# and customized materials
  • Service Temperature: -196°C to +1000°C
  • Compatible Media: Water, neutral gas, liquids, alcohol, oil, fuel, steam, organic solvents, acid and alkaline media
  • Application Industries: Oil & Gas, Chemical, Petrochemical, Power, Marine, Food & Beverage, Pharmaceutical, Water Treatment, HVAC, Metallurgy, and Environmental Engineering.

Product details

Socket Weld Flange, commonly abbreviated as SW Flange, is one of the most widely used types of forged flanges for small-diameter, medium-to-high pressure piping systems.

The pipe is inserted into the socket bore of the flange and positioned against the internal shoulder. A fillet weld is then applied around the outside of the flange hub, creating a permanent welded connection between the pipe and flange.

The two mating flanges are tightened together by bolts, compressing the gasket between the flange faces to achieve reliable face sealing performance.

Product Specifications

Note: The flange inner diameter (B) is determined by the wall thickness of the steel pipe and shall be specified by the user at the time of ordering.(Unit: mm)

SW-150LB-1500LB

DNNPSType/ClassPart NoADKLThnCB1B2UNHd1fPEFdwXyZ
15 0.5SW-150LB-SFTXLXSW150SFT0521.3 90 60.3 16 M144 9.6 15.5 22.5 10 30 14 35.11.5
20 0.75SW-150LB-SFTXLXSW150SFT07526.9 100 69.9 16 M144 11.2 21 27.5 11 38 14 42.91.5
25 1SW-150LB-SFTXLXSW150SFT133.7 110 79.4 16 M144 12.7 27 34.5 13 49 16 50.81.547.636.358.74
32 1.25SW-150LB-SFTXLXSW150SFT12542.4 115 88.9 16 M144 14.3 35 43.5 14 59 19 63.51.557.156.358.74
40 1.5SW-150LB-SFTXLXSW150SFT1548.3 125 98.4 16 M144 15.9 41 49.5 16 65 21 731.565.076.358.74
50 2SW-150LB-SFTXLXSW150SFT260.3 150 120.7 18 M164 17.5 52 61.5 17 78 24 91.91.582.556.358.74
65 2.5SW-150LB-SFTXLXSW150SFT2576.1 180 139.7 18 M164 20.7 66 77.6 19 90 27 104.61.5101.66.358.74
80 3SW-150LB-SFTXLXSW150SFT388.9 190 152.4 18 M164 22.3 77.5 90.5 21 108 29 1271.5114.36.358.74
150.5SW-300LB-SFTXLXSW300SFT0521.39566.716M14412.715.522.510382135.11.534.145.547.144625.434.936.523.8
200.75SW-300LB-SFTXLXSW300SFT07526.911582.618M16414.32127.511482442.91.542.886.358.745433.342.944.431.8
251SW-300LB-SFTXLXSW300SFT133.712588.918M16415.92734.513542550.81.550.86.358.746238.150.852.436.5
321.25SW-300LB-SFTXLXSW300SFT12542.413598.418M16417.53543.514642563.51.560.336.358.747547.663.565.146
401.5SW-300LB-SFTXLXSW300SFT1548.3155114.322M20419.14149.5167029731.568.276.358.7484547374.652.4
502SW-300LB-SFTXLXSW300SFT260.316512718M16820.75261.517843291.91.582.557.9211.911037392.193.771.4
652.5SW-300LB-SFTXLXSW300SFT2576.1190149.222M20823.96677.61910037104.61.5101.67.9211.9111685.7104.8106.484.1
803SW-300LB-SFTXLXSW300SFT388.9210168.322M2082777.590.521117411271.5123.837.9211.91138108127128.6106.4
150.5SW-600LB-SFTXLXSW600SFT0521.39566.716M14414.322.510382235.16.434.145.547.144625.434.936.523.8
200.75SW-600LB-SFTXLXSW600SFT07526.911582.618M16415.927.511482542.96.442.886.358.745433.342.944.431.8
251SW-600LB-SFTXLXSW600SFT133.712588.918M16417.534.513542750.86.450.86.358.746238.150.852.436.5
321.25SW-600LB-SFTXLXSW600SFT12542.413598.418M16420.743.514642963.56.460.336.358.747547.663.565.146
401.5SW-600LB-SFTXLXSW600SFT1548.3155114.322M20422.349.5167032736.468.276.358.7484547374.652.4
502SW-600LB-SFTXLXSW600SFT260.316512718M16825.461.517843791.96.482.557.9211.911037392.193.771.4
652.5SW-600LB-SFTXLXSW600SFT2576.1190149.222M20828.677.61910041104.66.4101.67.9211.9111685.7104.8106.484.1
803SW-600LB-SFTXLXSW600SFT388.9210168.322M20831.890.521117461276.4123.837.9211.91138108127128.6106.4
150.5SW-900LB-SFTXLXSW900SFT0521.312082.622M20422.322.510383235.16.439.676.358.744625.434.936.523.8
200.75SW-900LB-SFTXLXSW900SFT07526.913088.922M20425.427.511443542.96.444.456.358.745433.342.944.431.8
251SW-900LB-SFTXLXSW900SFT133.7150101.626M24428.634.513524150.86.450.86.358.746238.150.852.436.5
321.25SW-900LB-SFTXLXSW900SFT12542.4160111.126M24428.643.514644163.56.460.336.358.747547.663.565.146
401.5SW-900LB-SFTXLXSW900SFT1548.3180123.830M27431.849.5167044736.468.276.358.7484547374.652.4
502SW-900LB-SFTXLXSW900SFT260.3215165.126M24838.161.5171055791.96.495.257.9211.911037392.193.771.4
652.5SW-900LB-SFTXLXSW900SFT2576.1245190.530M27841.377.61912464104.66.4107.957.9211.9111685.7104.8106.484.1
150.5SW-1500LB-SFTXLXSW1500SFT0521.312082.622M20422.322.510383235.16.439.676.358.744625.434.936.523.8
200.75SW-1500LB-SFTXLXSW1500SFT07526.913088.922M20425.427.511443542.96.444.456.358.745433.342.944.431.8
251SW-1500LB-SFTXLXSW1500SFT133.7150101.626M24428.634.513524150.86.450.86.358.746238.150.852.436.5
321.25SW-1500LB-SFTXLXSW1500SFT12542.4160111.126M24428.643.514644163.56.460.336.358.747547.663.565.146
401.5SW-1500LB-SFTXLXSW1500SFT1548.3180123.830M27431.849.5167044736.468.276.358.7484547374.652.4
502SW-1500LB-SFTXLXSW1500SFT260.3215165.126M24838.161.5171055791.96.495.257.9211.911037392.193.771.4
652.5SW-1500LB-SFTXLXSW1500SFT2576.1245190.530M27841.377.61912464104.66.4107.957.9211.9111685.7104.8106.484.1

Forged construction: Manufactured from forged materials to provide high strength, durability, and excellent pressure resistance.

Socket welding connection: The pipe is inserted into the flange socket and secured by external fillet welding, ensuring a strong and permanent connection.

No internal pipe penetration welding required: Helps reduce welding deformation and simplifies installation.

Excellent vibration resistance: Suitable for piping systems subject to mechanical vibration and pressure fluctuations.

Compact structure: Ideal for small-diameter piping applications where space is limited.