Weld Neck Flanges

Posted by: NCTV in Flange January 21, 2014 0 1233 Views

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

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

Contents

1 Standards, Dimensions & Weight
2 Meterial & Standard for flanges:
- 2.1 CARBON STEEL
- 2.2 ALLOY STEEL
3 Dimensions are in millimeters unless otherwise indicated.Dimensional Tolerances of Weld Neck Flanges ASME B16.5

ASME B16.5 Class 300 WN
ASME B16.5 Class 600 WN
ASME B16.47 B 605 C 600 WN
ASME B16.47 B 605 C 900 WN
BS 3293 Class 150 WN
BS 3293 Class 300 WN
BS 3293 Class 600 WN
DIN 2631 PN 6
DIN 2632 PN 10
DIN 2633 PN 16
DIN 2634 PN 25
DIN 2635 PN40

ASME B16.5 Class 150 WN
ASME B16.5 Class 900 WN
ASME B16.5 Class 1500 WN
ASME B16.5 Class 2500 WN
ASME B16.47 A SP-44 C 150 WN
ASME B16.47 A SP-44 C 300 WN
ASME B16.47 A SP-44 C 600 WN
ASME B16.47 A SP-44 C 900 WN
ASME B16.47 B 605 C 75 WN
ASME B16.47 B 605 C 150 WN
ASME B16.47 B 605 C 300 WN

Meterial & Standard for flanges:

CARBON STEEL

ASTM A 105, ASTM A 181

ALLOY STEEL

ASTM A 182, GR F1, F11, F22, F5, F9, F91

Nickel Alloys
Monel 400 & 500, Inconel 600 & 625, Incolloy 800, 825, Hastelloy C22,C276

Copper Alloys
Copper, Brass & Gunmetal

Size
1/8″ NB TO 48″NB.

Class
150#, 300#,400 #,600#,900#, 1500# & 2500 #.

Standard ANSI
ANSI B16.5, ANSI B16.47, MSS SP44, ANSI B16.36, ANSI B16.48

DIN
DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655, DIN2656, DIN2627, DIN2628, DIN2629, DIN 2631, DIN2632, DIN2633, DIN2634, DIN2635, DIN2636, DIN2637, DIN2638, DIN2673

B.S
BS4504 , BS4504, BS1560, BS10

Dimensions are in millimeters unless otherwise indicated.Dimensional Tolerances of Weld Neck Flanges ASME B16.5

OUTSIDE DIAMETER

≤ 24 = 1.6 mm
> 24 = ± 3.2 mm

INSIDE DIAMETER

≤ 10 = ± 0.8 mm
≥ 12 = + 1.6 mm / – 0 mm

DIAMETER OF CONTACT FACE

1.6 mm Raised Face = ± 0.8 mm
6.35 mm Raised Face
Tongue & Groove / Male-Female = ± 0.4 mm

DRILLING

Bolt Circle = 1.6 mm
Bolt Hole Spacing = ± 0.8 mm
Eccentricity of Bolt Circle with Respect to Facing
≤ 2½ = 0.8 mm max.
≥ 3 = 1.6 mm max.

DIAMETER OF COUNTERBORE

Same as for Inside Diameter

OUTSIDE DIAMETER OF HUB

≤ 12 = + 2.4 mm / – 1.6 mm
≥ 14 = ± 3.2 mm

THICKNESS

≤ 18 = + 3.2 mm / – 0
≥ 20 = + 4.8 mm / – 0

LENGTH THRU HUB

≤ 18 = + 3.2 mm / – 0.8 mm
≥ 20 = + 4.8 mm / – 1.6 mm

From Metal & Oil & Gas News, post Weld Neck Flanges

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Weld Neck Flanges

Standards, Dimensions & Weight