ASTM A182 F5 Alloy Steel Weld Neck Flanges Alloy Steel Flange

ASTM A182 F5 ANSI B16.5/B16.47 Alloy Steel Weld Neck Flanges

Alloy steel weld neck flanges​ Information

An alloy steel weld neck flange is a type of flange made from alloy steel that features a weld neck design.

Alloy steel weld neck flanges are made from various alloy steel grades, such as ASTM A182 F5, F9, F11, F22, or F91. Alloy steel offers high strength, excellent corrosion resistance, and enhanced temperature resistance, making it suitable for applications in high-pressure and high-temperature environments.

Alloy steel weld neck flanges are available in a wide range of sizes, ranging from small diameters to large diameters, to accommodate different pipe sizes and system requirements.

Alloy steel weld neck flanges are available in a wide range of sizes, ranging from small diameters to large diameters, to accommodate different pipe sizes and system requirements.

The flanges are designed to withstand specific pressure ratings, such as Class 150, Class 300, Class 600, etc., depending on the application requirements. The pressure ratings determine the flange's ability to handle different operating pressures.

Alloy steel weld neck flanges have the ability to withstand high temperatures, making them suitable for applications involving elevated temperatures.

Standards & Materials: ASTM A182 F5

Chemical Composition of ASTM A182 F5 Alloy Flanges

Mechanical Properties of ASTM A182 F5 Alloy Flanges

Long Weld Neck Flanges (LWN)

This flange type is regarded as high-hub flanges, which were created so stress could be transferred to the pipe and decreasing the stress concentration at the bottom of the flange.

The long welding neck flange is mainly applied to the construction of pressure vessel functioning as a nozzle (such as a thermowell nozzle). To attach a common welding neck flange to a pressure vessel, a piece of pipe is required with additional welding. A LWN flange on the other hand attaches directly to the vessel, hence, it can be viewed as an integrally reinforced nozzle. It avoids making a weld seam at pipe to flange and provides self-reinforcement.

Reducing Weld Neck Flange

It is also called reducing welding neck flange, because the flange neck has a reducing diameter that to weld to a smaller diameter pipe.

The reducing weld neck flange is used to make a reduction in the diameter of the pipe. A reducing flanged joint consists of a reducing flange and a standard flange, functioning like a reducer fitting. As illustrated in Figure-1, the larger end of reducing flange A, which is in contact with the standard flange B, is known as “the size from which the reduction is being made”; the smaller end of the reducing flange A, which will be welded to a pipe, is known as “the size to which the reduction is being made”. The flow should travel from the smaller size to the larger. If the flow direction were reversed, severe turbulence could develop.

In order to make a reduction in the pipe line with two standard welding neck flanges, an additional reducer shall be used as illustrated in Figure-2. The overall length of this configuration is 2L+H, which is much longer than L+M of a reducing flanged joint as illustrated in Figure-1. It means that the use of reducing flanges can effectively save space in crowed situation. In fact, the reducing flange is most frequently used in installations with limited space.

Pressure-Temperature Ratings

Both ASME B16.5 and ASME B16.47 has stipulated pressure-temperature ratings for ASTM A182 F5 steel, which are maximum allowable working gauge pressures in psi units at the temperature in degrees Fahrenheit. The data sheet is divided by Classes: ASME B16.5 flanges are available in Class 150, 300, 400, 600, 900, 1500, 2500; ASME B16.47 Series A are available in Classes 150, 300, 400, 600, 900; and ASME B16.47 Series B are available in Classes 75, 150, 300, 400, 600, 900.

Manufacturing Process