Long Weld Neck Flange

• Design: A Long Weld Neck Flange is a type of flange with an extended neck or hub that gradually tapers from the pipe or vessel to the flange face. The extended neck provides a smooth transition between the pipe and the flange, reducing stress concentrations and providing additional strength. This design is particularly useful in high-pressure and high-temperature applications.


• Applications: Commonly used in critical applications where a strong and durable connection is required, such as in oil and gas, chemical processing, and high-pressure steam systems. The long neck helps to distribute stresses evenly and minimize the potential for stress concentration.


• Installation: The flange is welded to the pipe or vessel, creating a continuous, strong joint. The extended neck provides added strength and allows for a more gradual transition from the pipe to the flange face.

Chemical and Mechanical Properties Table

Material	Grade	Chemical Composition (wt%)	Yield Strength (MPa)	Tensile Strength (MPa)	Elongation (%)
Carbon Steel	ASTM A105	C: 0.35 max, Mn: 0.60-0.90, P: 0.035 max, S: 0.035 max	205 - 250	420 - 550	20
Stainless Steel	ASTM A182 F304	C: 0.08 max, Cr: 18.0-20.0, Ni: 8.0-10.5	205 - 310	510 - 720	40
Stainless Steel	ASTM A182 F316	C: 0.08 max, Cr: 16.0-18.0, Ni: 10.0-14.0, Mo: 2.0-3.0	205 - 310	510 - 720	40
Alloy Steel	ASTM A234 WP22	C: 0.12-0.20, Cr: 1.0-1.5, Mo: 0.4-0.6	205 - 275	485 - 620	20
High-Temperature Alloy	ASTM A182 F91	C: 0.05-0.15, Cr: 8.0-9.5, Mo: 0.85-1.05	415 - 485	620 - 825	20

Notes:

• Chemical Composition: Indicates the elemental makeup of the material. For example, ASTM A182 F304 stainless steel includes chromium and nickel for corrosion resistance.


• Yield Strength: The stress at which the material begins to permanently deform.


• Tensile Strength: The maximum stress that the material can endure while being stretched or pulled before breaking.


• Elongation: Measures the ductility of the material, indicating how much it can stretch before failing.