Pipe branch fitting

A mechanical coupling for connecting a branch pipe to a main pipe at a hole through the wall of the main pipe, comprising two opposed arcuate sections defining a cylindrical space therebetween for embracing the wall of the main pipe;

• a first of said arcuate sections including a concave saddle wall defining a portion of a cylindrical surface having a radius generally corresponding to the outer circumference of the main pipe, a radially extending branch pipe opening within said first arcuate section dimensioned to overlay the main pipe opening and communicate with said saddle wall, and a spigot wall surrounding said branch pipe opening, and terminating at said saddle wall;
• a radially extending gasket recess surrounding said spigot wall, said gasket recess having a radially inward open terminus at said saddle wall, and a radially outward wall terminus in the direction of the branch pipe;
• and
• a gasket for sealing engagement within said gasket recess and the main pipe, said gasket including:
• a first generally circumferential sealing surface at one radial end terminus of the gasket, positioned along the radially inward open terminus of said gasket recess for engagement with the outer circumference of the main pipe proximate said spigot wall, and providing a continuation of the saddle wall,
• a second generally circumferential sealing surface of the opposed radial end terminus of the gasket, in engagement with the radially outward wall terminus of the gasket recess, and
• a third generally circumferential sealing surface, radially intermediate said first and second generally circumferential sealing surfaces, in engagement with said saddle wall,
• whereby said gasket provides radially spaced first, second, and third generally circumferential sealing surfaces.