Forged flange is defined as a plate type device, normally round, that is attached to the end of a pipe, fitting, valve or other object to facilitate the assembly and disassembly of a piping system.
Forged flanges are manufactured in all the different materials to match the material of the pipe and fittings to which they are being attached. While some flanges are made of Cast Iron, the vast majority of flanges are forged carbon steel.
Forged steel flanges are made in seven primary ratings:
The various types of Forged steel flanges are:
A blind, or blanking, flange is a round plate with no center hold (but with bolt holes) that closes the ends of piping systems.
Lap Joint Flanges
Piping fitted with lapped pipe or with lap joint stub ends often use lap joint flanges. Also, systems frequently taken apart for inspection and cleaning often use lap joint flanges.
Orifice meters that measure the flow rate of either gases or liquids use orifice flanges.
When a change in diameter is required in a piping system, reducing flanges are used. A reducing flange has a specified diameter with a bore of a different, smaller diameter.
Slip-on flanges slide over the end of a pipe and are then welded into place. These flanges work well for low-pressure applications.
Socket Weld Flange
The socket weld flange is counter-bored to accept the pipe before being fillet welded. This type of flange is similar to a slip-on flange. The bore of the pipe and flange are the same, which provides good flow characteristics.
Threaded flanges, which are threaded in the bore to match an external thread on the pipe, are attachable to a pipe without welding.
Weld Neck Flanges
Weld neck flanges have a long tapered hub and are often used for high-pressure applications. The pipe and flange bores match, which reduces turbulence and erosion inside the pipeline.