flange

Flanged railway wheel

A flange is an external or internal rib, or rim (lip), for strength, as the flange of an iron beam or I-beam (or a T-beam); or for a guide, as the flange of a train wheel; or for attachment to another object, as the flange on the end of a pipe, steam cylinder, etc, or on the lens mount of a camera. Thus a flanged rail is a rail with a flange on one side to keep wheels, etc., from running off. The term "flange" is also used for a kind of tool used to form flanges. By the use of Flanges we can assemble or dissamble the pipes very easily.

Plumbing or Piping

See main article Plumbing or Piping

Although flange generally refers to the actual raised rim or lip of a fitting, many flanged plumbing fittings are themselves known as 'flanges':

Surrey Flange

Common flanges used in plumbing are the Surrey flange or Danzey flange, York flange, Sussex flange and Essex flange. Surrey and York flanges fit to the top of the hot water tank allowing all the water to be taken without disturbance to the tank. They are often used to ensure an even flow of water to showers. An Essex flange requires a hole to be drilled in the side of the tank.

There is also a Warix flange which is the same as a York flange but the shower output is on the top of the flange and the vent on the side. The York and Warix flange have female adapters so that they fit onto a male tank, whereas the Surrey flange connects to a female tank.

A closet flange provides the mount for a toilet.

Pipe flanges

There are many different flange standards to be found worldwide. To allow easy functionality and inter-changeability, these are designed to have standardised dimensions. Common world standards include ASA/ANSI (USA), PN/DIN (European), BS10^[1] (British/Australian), and JIS/KIS (Japanese/Korean).

In most cases these are not interchangeable (eg an ANSI flange will not mate against a JIS flange). Further many of the flanges in each standard are divided into "pressure classes", allowing flanges to be capable of taking different pressure ratings. Again these are not generally interchangeable (eg an ANSI 150# will not mate with an ANSI 300#). These "pressure classes" also have differing pressure and temperature ratings for different materials. "Pressure Classes" of piping are usually developed for a process plant or power generating station; these "pressure classes" may be unique to the specific corporation, Engineering Procurement and Construction (EPC) contractor, or the process plant owner.

The flange faces are made to standardized dimensions and are typically "flat face", "raised face", "tongue and groove", or "ring joint" styles, although other obscure styles are possible.

Flange designs are available as "welding neck", "slip-on", "boss", "lap joint", "socket weld", "threaded", and also "blind".

ANSI/ASME standards (U.S.)

ASME type flange on a gas pipeline

Pipe flanges that are made to standards called out by ASME/ANSI B16.5 or ASME/ANSI B16.47 are typically made from forged materials and have machined surfaces. They are typically in "Pressure Classes" such as 150#, 300#, 600#, 900# 1500#; however, ASME B16.47 still recognizes the 75# or "Class 75" flange for certain low pressure and low temperature applications.

The gasket type and bolt type are generally specified by the standard(s); however, sometimes the standards refer to the ASME Boiler and Pressure Vessel Code (B&PVC) for details (see ASME Code Section VIII Division 1 - Appendix 2). These flanges are recognized by ASME Pipe Codes such as ASME B31.1 Power Piping, and ASME B31.3 Process Piping.

Materials for flanges are usually under ASME designation: SA-105 (Specification for Carbon Steel Forgings for Piping Applications) , SA-266 (Specification for Carbon Steel Forgings for Pressure Vessel Components) or SA-182 (Specification for Forged or Rolled Alloy-Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service).

Other countries

Flanges in other countries also are manufactured according to standards for materials, pressure ratings, etc. Such standards include DIN, BS and/or ISO standards.

Vacuum flanges

A vacuum flange is a flange at the end of a tube used to connect vacuum chambers, tubing and vacuum pumps to each other.

Form factor of PDR and CBR flanges.

Microwave RF

In microwave telecommunications, a flange is a type of cable joint which allows different types of waveguide to connect.

Several different microwave RF flange types exist, such as CAR, CBR, OPC, PAR, PBJ, PBR, PDR, UAR, UBR, UDR, and UPX.

References

• ASME B16.5 Standard Pipe Flanges up to and including 24 inches nominal
• ASME B16.47 Standard Pipe Flanges above 24 inches
• ASME Section II (Materials), Part A - Ferrous Material Specifications
• Nayyar, Mohinder (1999). Piping Handbook, Seventh Edition. New York: McGraw-Hill. ISBN 0070471061.