Weld neck flange and long weldneck flange provide reinforcement in application requiring high pressure and during low and high pessure extremes. It also helps in low cycle fatigue caused by line expansion of other variable forces.
Weldneck flange bore is machined to match the ID of the pipe or fitting. This creates a smooth transition to and from the weld neck flange and prevents turbulence at the welding neck. Hence it is important to specify the pipe schedule at the time of buying a weld neck flange. Weldneck flange is welded to pipe with full penetration weld and provides excellent stress distribution through tapered neck. Weld is also routinely radiographed or UT examined in critical applications.
Weld neck flange is available in both raised face and flat face configuration. Most common weld neck flanges have standard bore or extra heavy bore. Sch 120 or Sch 160 bore flanges, in heavier weights such as 600# to 1500# are also common in weld neck flange.
Weld Neck Flange Specification:
Size |
1/2" to 60" |
Class |
150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS. |
Flange Face Type |
Flat Face(FF), Raised Face(RF),RTJ |
Surface Treatment |
Antirust Paint, Oil Black Paint, Yellow Transparent,Hot Dip Galvanized |
Materal |
Stainless Steel, Alloy Steel, Carbon Steel, |
Manufacturing process |
Cutting, Heat treatment, Die Forging/Free Forging, CNC Machining |
Manufacturing Standards |
ANSI B16.5, ANSI B16.47 Series A & B, MSS SP44, API-605 |
Material Grades:
Stainless Steel |
ASTM A 182F 304, 304L, 304H, 316, 316L, 316Ti, 321, 321H, 347 |
Carbon Steel |
ASTM/ ASME A 105, ASTM/ ASME A 350 LF 2 |
Alloy Steel |
ASTM / ASME A 182, ASTM / ASME F5, F9, F11,F22, F 91 |
Weld Neck Flanges
in three types of paintings:
♦ Anti-Rust Oil Painting
♦ Yellow Golden Painting
♦ Black Painting
International Standards:
American Standard
ASME/ANSI B 16.5, ASME B 16.47 SERIES A(MSS SP 44), ASME B 16.47 SERIES B(API 605)
Pressure Ratings:
150LB, 300LB, 400LB, 600LB, 900LB, 1500LB, 2500LB;
Size Range: 1/2" ~ 60"
Used in: Oil & Gas, Offshore, Water, Ship, Power, Pipe Projects etc.
Weld neck flanges are typically provided with a raised face, flat face, or RTJ facing. When a raised face is necessary for weld neck flanges, the standard height is 1/16″ for weld neck flanges fewer than 400#. For weld neck flanges of 400# and up, the standard weld neck flange raised face height is 1/4″.
Weld Neck Flange is flanges that designed to be joined to a piping system by butt welding. This kind of flange include lots of specification,Weld neck Flange is expensive because of its long neck and cost of people for contact WN flange with pipeline or fitting, but is preferred for high stress applications. The necks, or hubs, transmits stresses to the pipeline.
The gradual transition of thickness from the base of the hub to the wall thickness at the butt weld provides important reinforcement of the Weld Neck flange. The bore of Weld-Neck flange matches bore of the pipeline, reducing turbulence and erosion.
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