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 B16.47 Flange  Class 150-900 Series A – 26″to 60″
  • ASME B16.47 Flange  Class 75-900 Series B – 26″to 60″

lewis Liu

sales Manager

Weld Neck Flanges

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

TypeWeld Neck Flange – A type of flange with a long tapered neck that is butt-welded to the pipe, providing excellent strength and stress distribution.
Pressure RatingsAvailable in different pressure classes, such as 150, 300, 600, 900, 1500, 2500, etc., to accommodate varying pressure requirements.
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.

Welding Neck Flanges are easy to recognize at the long tapered hub, which goes gradually over to the wall thickness from a pipe or fitting.

The long tapered hub provides an important reinforcement for use in several applications involving high pressure, sub-zero and/or elevated temperatures. The smooth transition from flange thickness to pipe or fitting wall thickness affected by the taper is extremely beneficial, under conditions of repeated bending, caused by line expansion or other variable forces.

These flanges are bored to match the inside diameter of the mating pipe or fitting so there will be no restriction on product flow. This prevents turbulence at the joint and reduces erosion. They also provide excellent stress distribution through the tapered hub and are easily radiographed for flaw detection.
This flange type will be welded to a pipe or fitting with a single full penetration, V weld (Buttweld).

The Weld Neck Flange offers increased strength under higher pressures, subzero or elevated temperatures that cause line expansion or retraction or other variable forces. The Slip On Flange is connected to the pipe by two welds, one on the back side of the Flange and one on the inside of the Flange.

Weld neck flange is available in both raised-face and flat-face configurations. 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 flanges.

Flanges are helpful to connect pumps, valves, pipes, and other parts to form a piping system. Flanges are typically welded or thread screwed to connect. The use of flanges allows a person to maintain and easily repair the pipe system.

A welding neck flange (“WN”)features a long tapered hub that can be welded with a pipe. This flange type is used, normally, in high-pressure and high/low temperatures applications that require an unrestricted flow of the fluid conveyed by the piping system (the bore of the flange matches with the bore of the pipe).

Any butt-weld fitting or weld-neck flange can be directly welded to any other butt-weld fitting or weld-neck flange without the need for any extra piece of pipe (Pup piece) between them.

There are two types of weld neck flanges, which are standard and long. Standard weld neck flanges are used in butt weld fittings. Long weld neck flanges are used with vessel nozzles and equipment. The flanges are created to match the pipe’s inside diameter or fitting.