Weld Neck Flanges

Our company provides Weld Neck Flanges.

We provide flange products of various standards such as American standards, European standards, German standards, and Japanese standards. The list of common standards is as follows:

  • ASME/ANSI B16.47 Class 150-900 Series A Welding Neck Flanges – 26″to 60″
  • ASME/ANSI B16.47 Class 75-900 Series B Flange  – 26″to 60″
  • ASME/ANSI B16.5 Class 150-2500 Series B Welding Neck Flanges– 1/2″to 24
Weld Neck Flanges

lewis Liu

sales Manager

Weld Neck Flanges

Weld neck flange has a long neck in the middle for butt welding with pipes. So it is also called high neck flange or long neck flange. Often used in high temperature and high pressure and pipe diameter is relatively large pipeline.

Weld neck flange is commonly standardized as ASME B16.5 and ASME B16.47, with sizes ranging from 1/2-inch to 60-inch, and sealing surface types including raised face (RF), flat face (FF), dimpled face (MFM), tongue and groove (TG), ring joint (RJ), and so on. Applicable pressure classes include Class150, 300, 400, 600, 900, 1500, 2500 and other 7 classes. Common materials include stainless steel F304/304L, F316/316L, F321, F347, F904L, F51, F53, F55 and so on.

Here is a table outlining the specifications and characteristics of Weld Neck Flanges:

AppearanceWeld Neck Flange is disk-shaped, in which there is a raised neck called flange neck, flange neck around a number of bolt holes.
Pressure Ratingsclass15(PN16), class300(PN25),class600(PN50), class900(PN64), class1500(PN260), class2500(PN420).
Size RangeTypically available in sizes ranging from 1/2 inches to 48 inches or larger, suitable for various pipe and equipment sizes.
MaterialsWeld Neck Flanges can be manufactured from materials like carbon steel, stainless steel, alloy steel, and more, chosen based on application requirements.
Facing TypesCommon facing types include Raised Face (RF), Flat Face (FF), Ring-Type Joint (RTJ), and Male and Female (M&F) facings, impacting sealing methods.
Bolt Hole Quantity and DiameterThe number and diameter of bolt holes vary with flange size and pressure rating, facilitating flange connection.
Connection MethodWeld Neck Flanges are butt-welded to the pipe, providing a strong and leak-resistant connection.
Application AreasWeld Neck Flanges are widely used in industries such as oil and gas, petrochemical, power generation, and more for connecting high-pressure piping systems.
Standards and CodesWeld Neck Flanges adhere to standards set by the American National Standards Institute (ANSI) and nominal pipe size (NPS) standards, such as ANSI B16.5.
Seal TypesWeld Neck Flanges commonly use gaskets or O-rings for sealing, with the choice of seal type depending on the application and pressure rating.
Accessories and AttachmentsSome applications may require additional components such as flange gaskets, bolts, nuts, flange covers, or flange cover gaskets.
Inspection and TestingWeld Neck Flanges typically undergo a series of inspections and tests to ensure they meet quality and performance requirements, in compliance with standards.
Marking and CertificationWeld Neck Flanges should be marked with the manufacturer’s identification, size, class, material, and other relevant information. Some flanges may require specific certifications such as PED or ASME.
Installation and MaintenanceProper installation and regular maintenance of Weld Neck Flanges, including weld integrity, bolt torque, flange face cleaning, and seal replacement, are crucial for system integrity and performance.
Application StandardsIn specific industries and applications, there may be industry-specific Weld Neck Flange application standards that need to be adhered to for safety and performance.
Weld Neck Flanges Main Features and Specifications Table

This table provides a comprehensive overview of Weld Neck Flanges, covering key specifications, characteristics, and additional considerations. Specific details and requirements may vary based on the chosen flange size, pressure rating, and material.

A weld neck flange is a flange with a raised neck in the center for butt-welding to a pipe.

The weld neck flange is not suitable for high pressure and flammable and explosive places.

The weld neck flange is suitable for pipelines with a high sealing requirement at a nominal pressure of 0.25-4MPa.

The most common materials for weld neck flange are stainless steel, carbon steel and alloy steel.

The installation steps of weld neck flange are as follows: preparation, cleaning the flange surface, installing the sealing gasket, centering the flange and pipe fittings, spot welding to fix the flange initially, full welding to ensure that the sealing surface and pipe fittings are completely adhering to each other, checking whether the connection is solid and there is no leakage, and then finish the work.

The weld neck flange is cost-effective, easy to fabricate, has good sealing and can be used in places with high pressure.

There are two types of sealing surfaces for weld neck flanges: flat surfaces and protruding surfaces.

The most common sizes of weld neck flange are 1/2 inch – 60 inches.

The manufacturing process of weld neck flange is mainly material selection-heating-forging-heat treatment-machining-inspection-surface treatment, you can contact us if you want to know more specific and detailed manufacturing process.

The price of weld neck flange is affected by many factors such as steel price, flange size, pressure, etc. and transportation cost, manufacturer’s labor site cost, etc., so I can’t provide you with the specific price, if you need, please send us an email to tell us your detailed requirements and we will reply with a detailed quotation in the earliest time for you.