Before revision: Orangeburg pipe, showing its characteristic delamination in layers of compressed oil tar pitch-impregnated ground wood fibers Orangeburg pipe (also known as "fiber conduit", "bituminous fiber pipe" or "Bermico") is bitumen| bituminized fiber pipe made from layers of ground wood pulp fibers compressed with and bound by a water resistant adhesive then impregnated with liquefied coal tar pitch.Coal Tar Impregnated Wood Fibre Pipe", Jon C. Schladweiler, P.E., R.L.S.
After revision: Orangeburg pipe, showing its characteristic delamination in layers of compressed oil tar pitch-impregnated ground wood fibers Orangeburg pipe (also known as "fiber conduit", "bituminous fiber pipe" or "Bermico") is bituminized fiber pipe made from layers of ground wood pulp fibers compressed with and bound by a water resistant adhesive then impregnated with liquefied coal tar pitch.Coal Tar Impregnated Wood Fibre Pipe", Jon C. Schladweiler, P.E., R.L.S.