Weld Neck Flange
Product Description
Weld neck flanges are the most popular flange type with a neck extension with a weld bevel at the end. This type of flange is designed to butt weld directly to pipe to provide a superior and relatively natural form connection. In larger sizes and higher pressure classes, this is almost exclusively the type of flange connection utilized. If only one bored flange style existed in modern applications, the weld neck would be your flange of choice.The weld bevel joins to a pipe end with a similar bevel in a V-type connection which allows for a uniform circular weld around the perimeter to form a unified transition. This allows for the gas or liquid within the pipe assembly to flow with minimal restriction through the flange connection. This weld bevel connection is inspected after the weld procedure to ensure that the seal is uniform and lacking anomalies.
Typical Applications
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food and food processing industries.
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sewage and water treatment plants.
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risers for oil platforms and pipelines.
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ships and marine equipment.
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pharmaceutical industry.
Weldability
Good
Availability
Key features
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Nice corrosion resistance
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Good abrasion resistance
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Low magnetism
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Long working life
Corrosion Resistance
Very Good
Machinability
Good / fair.
Weld Neck Flange specifications
Chemical Composition (weight %)
| C | Si | Mn | P | S | Tensile strength kg/mm² |
Yield point kg/mm² |
Elongation% |
| 0.25 or less |
0.35 or less |
0.30 0.90 |
0.040 or less |
0.040 or less |
52 up | 39 up | 15 up |
| 38 up | 22 up | 30 up |
Mechanical Properties
| Grades | Delivery Conditions | Tensile Strength Rm (Mpa) | Elongation in the longitudinal direction Al (%) |
| St 45 | +A (GBK) | 390 min | 21 min |
| St 52 | +A (GBK) | 490 min | 22 min |
| E355 | +A (GBK) | 450 min | 22 min |
| 1020 | +A (GBK) | 390 min | 21 min |