Types of Flange Gaskets

a flange gasket is a type of gasket made to fit between two sections of pipe that are flared to provide higher surface area. flange gaskets come in a variety of sizes and are categorized by their inside diameter and their outside diameter.

there are many standards in gasket for flanges of pipes. the gaskets for flanges can be divided in major 4 different categories:

sheet gaskets – when a sheet of material has the gasket shape “punched out” of it, it is a sheet gasket. this can lead to a crude, fast and cheap gasket. in previous times the material was compressed asbestos, but in modern times a fibrous material or matted graphite is used. these gaskets can fill various different chemical requirements based on the inertness of the material used. non-asbestos gasket sheet is durable, of multiple materials, and thick in nature. material examples are mineral, carbon or nitrile synthetic rubber. applications using sheet gaskets involve acids, corrosive chemicals, steam or mild caustics. flexibility and good recovery prevent breakage during installation of a sheet gasket.

corrugated metal gaskets – these gaskets consist of a thin metal that is corrugated or embossed with concentric rings

and faced with a soft material such as flexible graphite.

ring gaskets – ring gaskets also known as rtj – style r, rx, bx (for rtj flange faces). they are mostly used in offshore oil- and gas pipelines and are designed to work under extremely high pressure. they are solid rings of metal in different cross sections like oval, round, octagonal etc. sometimes they come with hole in center for pressure .

spiral wound gaskets – spiral-wound gaskets comprise a mix of metallic and filler material. generally, the gasket has a metal (normally carbon rich or stainless steel) wound outwards in a circular spiral (other shapes are possible) with the filler material (generally a flexible graphite) wound in the same manner but starting from the opposing side. this results in alternating layers of filler and metal. the filler material in these gaskets acts as the sealing element, with the metal providing structural support. these gaskets have proven to be reliable in most applications, and allow lower clamping forces than solid gaskets, albeit with a higher cost.