B type cast iron pipe fittings for drainage GB/T12772-2008 1. Material: gray cast iron 2. Application: B B type cast iron pipe fittings for drainage GB/T12772-2008cast iron drainage pipe and fittings, soil pipes, cip, pipe fittings, coupling, astm a888, en877, astm a74, bs 437Hubless/socketless Cast Iron Soil/drainage Pipes and fittings has long been employed by the building industry as a ...