China Weld Neck Flange Factory: High-Performance Suppliers for Oil and Gas Pipeline Connections

Weld neck flanges, commonly known as wn flanges, are essential components in high-performance pipe connections, specifically engineered for high-pressure and high-temperature applications. These flanges feature a long tapered hub that is butt-welded to pipelines, ensuring exceptional strength and optimal stress distribution. Due to their reliability in extreme conditions, weld neck flanges are widely utilized in critical industries such as oil & gas, petrochemical, and power generation.

Quick Details

Parameter	Details
Type	Regular and Long Neck
Outside Diameter	1/2”~48” (DN15~DN1200)
Class	PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, PN250, PN320, PN400 Class 150, 300, 600, 900, 1500, 2500lb
Standards	EN 1092-1, ANSI/ASME B16.5, DIN2630-DIN2638, JIS B2220, ASME B16.47 Series A

As a leading China supplier and factory for weld neck flanges, we ensure the highest quality and performance standards, catering to the specific needs of our clients in demanding industrial sectors. Choosing our products guarantees reliability and excellence in demanding applications.

Product Details

Material Grade

Carbon Steel

ASTM A105 / A105N, ASTM A350 LF2 / LF3, ASTM A694 F42 / 46 / 56 / 60 / 65

Stainless Steel

ASTM A182 F304/304L/304H, 316/316L, 310S, 317, 347, 904L, ASTM A182 F51, F53, F44

Alloy Steel

ASTM A182 F11 / 12 / 5 / 9 / 91 / 92

Sealing Face:

RF FF FTJ

Frequently Asked Questions

Q What carbon steel grades are available for flanges?

Carbon steel flanges are available in ASTM A105 / A105N, ASTM A350 LF2 / LF3, and ASTM A694 F42 / F46 / F56 / F60 / F65, covering a wide range of pressure and temperature applications.

Q Which stainless steel grades are offered?

Stainless steel options include ASTM A182 F304/304L/304H, 316/316L, 310S, 317, 347, and 904L, as well as duplex and super duplex grades F51, F53, and F44 for high-corrosion environments.

Q What alloy steel grades are available?

Alloy steel flanges are manufactured to ASTM A182 grades F11, F12, F5, F9, F91, and F92, which are commonly used in high-temperature and high-pressure piping systems.

Q What sealing face types are available?

Three sealing face types are available: Raised Face (RF), Flat Face (FF), and Female-Tongue-and-Groove Joint (FTJ). The choice depends on the gasket type and pipeline requirements.

Q What is the difference between ASTM A105 and A105N?

ASTM A105N refers to ASTM A105 material that has been normalized — a heat treatment process that refines the grain structure, improving mechanical properties and toughness, especially for low-temperature service conditions.

Q When should duplex stainless steel grades like F51 or F53 be selected?

Duplex grades such as F51 (2205) and F53 (2507 super duplex) are recommended for applications involving chloride-containing environments, seawater, or aggressive chemical media, where standard austenitic stainless steels may suffer from pitting or stress corrosion cracking.