Flange

Flanges are a method of connecting pipes, valves, pumps, and other equipment to form a piping system, usually by welding or threading. It is also easy to clean, inspect or modify. Flanges are usually welded or tightened. Flange joints are made by bolting two flanges together and using washers between them to provide a seal.

Pipe assemblies may be bolted together between flanges. Flanges are used to connect pipes to each other, to valves, to fittings, and to special items such as filters and pressure vessels. Cover plates can be connected to create "blind flanges". Flanges are bolted together, and sealing is usually done using washers or other methods. Industries dealing with flammable, volatile, toxic or corrosive substances require special protection at flange joints. Flange shields can provide an additional level of protection to ensure safety.

There are many different flange standards worldwide. For simple functionality and interchangeability, these designs have standardized dimensions. Common world standards include ASA/ASME (USA), PN/DIN (Europe), BS10 (UK/Australia) and JIS/KS (Japan/Korea).

In most cases, standards are interchangeable, as most local standards have been aligned with ISO standards.

Flanges are also made in standardized sizes, usually in "flat", "convex", "mortise" or "ring joint" styles, but other ambiguous styles may be available.

Flange designs include "weld neck", "socket", "lap", "socket weld", "thread" and "blind flange".