Types of Forged Flanges – Part 1

Western of Texas Forge and Flange manufactures and delivers quality custom and standard forged flanges in a variety of materials like stainless steel and nickel while meeting all ASME and MSS industry and statutory standards. Of the flanges we forge daily here are several types to consider.

Weld Neck Flange. This type of forged flange has a long-tapered neck that is welded to the pipe. The flange has bolt holes that allow it to be bolted to another flange or a piece of equipment. The weld neck flange is used in high-pressure and high-temperature applications, such as in oil and gas pipelines, chemical plants, and refineries.

Long Weld Neck Flange. A Long Weld Neck Flange connection is the most cost-effective and lightweight choice among FCI standard connections when minimal reinforcing area is needed. It is extensively used as a nozzle in the ASME pressure vessel industry, particularly for its lightweight wall. The next in line is the Heavy Barrel (HB) nozzle, which has a slightly heavier wall barrel than the LWN.

The Intermediate 1 (I-1), Intermediate 2 (I-2), and Intermediate 3 (I-3) nozzles progressively have heavier wall types as indicated by their names. The Equal Barrel (E) is the last member of the nozzle family, characterized by its barrel OD equaling the flange OD. It is considered the heaviest wall nozzle according to the industry standard. However, larger barrel than flange diameter nozzles can be manufactured and identified as the Super Barrel (SB).

Slip-On Flanges. Slip-On Flanges, initially developed for high pressure piping in smaller sizes, Socket Weld flanges offer static strength equal to Slip On flanges, while their fatigue strength surpasses that of double-welded Slip On flanges by 50%. To connect the flange with the pipe, a single fillet weld is made on the outside. However, before welding, a gap must be created between the flange or fitting and the pipe.

The purpose of the gap in Socket Welds is typically to reduce residual stress that could arise during solidification of the weld metal at the root of the weld. The image provides the measurement of the expansion gap, where caution is needed to ensure it is appropriate.

Flat-Bottomed Flange. A Flat-Bottomed Flange with an outlet or nozzle positioned at the base is known as a Studding Outlet Flange. The central aperture serves as a connection point for linking pipelines or equipment through a studded fastening mechanism, typically utilizing bolts or studs that are screwed into the flange and secured onto the equipment. A popular component in industries like oil and gas, chemical processing, and power generation, studding outlet flanges have widespread usage.

For quality pipe flanges and other custom forgings, contact our support sales team at 409-246-2427or request a quote with our online form here – Request a Quote.