ASME B16.5 Weldneck Flange For High Pressure Piping Systems

ASME B16.5 Weldneck Flange For High-Pressure Piping Systems

Specifications

The ASME B16.5 Weld Neck Flange (also known as a Welding Neck Flange or WN Flange) is a forged flange designed for butt-welding directly to the pipe. Manufactured in accordance with ASME B16.5 dimensional standards, this flange features a long, tapered hub that provides gradual stress transition and a bore that precisely matches the pipe inside diameter, ensuring smooth flow and exceptional strength.

Material: 

• Carbon steel :A105, C22.8, S235, S235JR, P235GH,SS400,37.2
• Stainless Steel :F 304, 304L, 304H, 316, 316Ti, 316H, 316L, 316LN, 309S, 309H, 310S, 310H,317, 317L, 321, 321H, 347, 347H, 201, 202, 904L,1.4301, 1.4404
• Alloy Steel: ASTM A234 WP1/5/9/11/12/22/91,DEPLEX S31803/F51,S32750/F53
• Duplex stainless steel: UNS31803, SAF2205, UNS32205, UNS3150

Types of Pipe Flanges

There are several types of pipe flanges in a piping system; but there are 6 main types – blind, lap joint, slip on, socket weld, threaded and weld neck.  Each of them has properties that determine their use in commercial, industriall and institutional applications.

Blind flanges

No center hole and are used to seal off a piping system.  As a result, one can easily execute pressure tests cost effectively. 

Lap Joint flanges

Use a stub end (Type A, B or C) and slide over the pipe.  They are also known as loose-ring flanges and back-up flanges.  Lap joint is used with lapped pipe and allow for frequent cleaning and inspection through dismantling.  They are very durable and can be used because the fluid conveyed in the system does not come in contact with the flange.

Slip On flanges

Also known as hubbed flanges, are thinner than other flanges and are traditionally used in low pressure systems.  This type slips onto the pipe and the fillet weld is applied at both the top and bottom of the pipe flange.  These welds provide extra strength and prevent leakage.  While the installation is low cost and easy, the welding does add cost to its installation.

Socket Weld flanges

Designed for small size, high-pressure piping systems that do not carry corrosive fluids.  The pipe is inserted into the socket and a single fillet weld on the outside of the flange is applied.

Threaded flanges

Used in applications that are low pressure on smaller, thick walled pipes.  Given their threaded connection, they do make it easy to disconnect the piping system.

Weldneck flanges

Have a long neck that is butt welded to pipe.  This type is also known as a weld bend flange.  Since the bore of the neck matches that of the pipe, it reduces erosion and turbulence.

There are other types of flanges including:  orifice, reducing, ductile iron backup, copper solder joint and many more.

Flange facing

There are three primary types of flange facings.  Not all facings are available with each end connection.  This is based on the design of the flange and design of the piping system.  

Raised Face Flanges (RF)

Flat Face Flanges (FF) 

Ring Type Joint Flanges (RTJ)

Flange pressure classes

Flanges are normally manufactured in seven basic ratings: 150 Lb, 300 Lb, 400 Lb, 600 Lb, 900 Lb, 1500 Lb and 2500 Lb.  The ratings can be expressed in different ways but mean the same thing - 150 Lb, 150 Lbs, 150# or Class 150.

Standard of Flange (Material)

Manufacturing Process of Pipe Flanges

ASME B16.5 Weldneck Flange Application

• High-Pressure Piping Systems
• High-Temperature Service
• Critical and Hazardous Services
• Oil and Gas Industry
• Chemical and Petrochemical Processing
• Power Generation Facilities
• Refinery and Hydrocarbon Processing
• Pressure Vessel and Equipment Connections

Packing & Loading

Flange inspection

Pipe Flanges is transported in containers