1. n. [Well Completions]

A connection profile used in pipe work and associated equipment to provide a means of assembling and disassembling components. Most oilfield flanges feature a bolt-hole pattern to allow the joint to be secured and a gasket profile to ensure a pressure-tight seal. The design and specification of a flange relates to the size and pressure capacity of the equipment to which it is fitted.

2. n. [Production]

A formed pipe fitting consisting of a projecting radial collar with bolt holes to provide a means of attachment to piping components having a similar fitting. The end piece of flanged-end valves.

See: fitting