Flangeless

Flangeless is an adjective used to describe a component or assembly that lacks a flange, the projecting rim used for bolting, sealing, or locating parts in a system. The term is formed from flange plus the suffix -less.

In piping and related equipment, flangeless configurations connect by methods other than flange mating, such as butt welding, socket welding, threading, or the use of clamps or couplings. Flangeless sections may be found in compact layouts, temporary installations, or where corrosion resistance, weight reduction, or cost concerns favor alternative joining methods.

Benefits of flangeless designs can include reduced weight, lower part count, and simpler fabrication or shorter installation times. They may also minimize flow disruption compared to flange-based connections. However, such designs often require skilled fabrication (for welding or threading), can complicate disassembly and maintenance, and may pose different sealing challenges that demand careful joint preparation and testing.

In other mechanical contexts, flangeless describes shafts, hubs, or gears that do not incorporate a flange for mounting, locating, or stopping movement. Components without a flange typically rely on shoulders, keys, set screws, clamps, or mating surfaces to achieve alignment and retention.

See also: flange, flanged connection, piping fittings, mechanical fastening.