Weld-Neck flanges or welding-neck flanges can be differentiated from all other types of flange by their long tapered hub. In addition, there is also a gentle transition of thickness in the region of the butt weld that joins them to pipe or a fitting. Weld-Neck flanges or welding-neck flanges are best suited for severe service conditions, whether loading conditions are substantially constant or fluctuate between wide limits.
Weld Neck Flanges are flanges with the wall thickness of the flange having the same dimensions of the matching pipe, the lighter the pipe is, the larger the bore, conversely, the heavier the pipe, the smaller the bore, they are normally used for high pressure, cold or hot temperature.
The various types of steel weld neck flanges are:
- Weld Neck Flat Face Flanges
- Raised Face Weld Neck Flanges
- Long Neck Weld Flanges
Standards, Dimensions & Weight
Meterial & Standard for flanges:
ASTM A 105, ASTM A 181
ASTM A 182, GR F1, F11, F22, F5, F9, F91
Monel 400 & 500, Inconel 600 & 625, Incolloy 800, 825, Hastelloy C22,C276
Copper, Brass & Gunmetal
1/8″ NB TO 48″NB.
150#, 300#,400 #,600#,900#, 1500# & 2500 #.
ANSI B16.5, ANSI B16.47, MSS SP44, ANSI B16.36, ANSI B16.48
DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655, DIN2656, DIN2627, DIN2628, DIN2629, DIN 2631, DIN2632, DIN2633, DIN2634, DIN2635, DIN2636, DIN2637, DIN2638, DIN2673
BS4504 , BS4504, BS1560, BS10
Dimensions are in millimeters unless otherwise indicated.Dimensional Tolerances of Weld Neck Flanges ASME B16.5
≤ 24 = 1.6 mm
≤ 10 = ± 0.8 mm
DIAMETER OF CONTACT FACE
1.6 mm Raised Face = ± 0.8 mm
Bolt Circle = 1.6 mm
DIAMETER OF COUNTERBORE
Same as for Inside Diameter
OUTSIDE DIAMETER OF HUB
≤ 12 = + 2.4 mm / – 1.6 mm
≤ 18 = + 3.2 mm / – 0
LENGTH THRU HUB
≤ 18 = + 3.2 mm / – 0.8 mm