Spectacle blind flanges, ANSI B16.5, are typically used to join and permanently confine pipe systems. Such A steel plate with two precisely sized circles cut out of it is disabled from the outside. A steel component that resembles the nose piece of glasses connects these two rings. Its interior width is the same as a flange, and one of the circles represents a sturdy plate and the oth... https://www.shasanpiping.com/spectacle-blined-flanges-manufacturers-exporters-suppliers-stockists.html