Face-to-face positive restrained rotating pipe flange

摘要

An annular ductile iron flange of nominal size has a non-threaded inner longitudinal surface defining an inner diameter that exceeds the outer diameter of a corresponding length of hubless ductile iron pipe of nominal thickness. The flange also has a basal surface with both a plurality of evenly spaced bolt holes and an annular counterbore adjacent to the inner longitudinal surface. The counterbore has a longitudinal depth slightly larger than the nominal thickness and a radial depth slightly larger than twice the nominal thickness. The flange is coupled to, and configured to rotate longitudinally around, the length of pipe. The bell end of the pipe is machined to an annular stub configured to recess into the counterbore. A threaded annular ductile-iron flange may be screwed onto the spigot end of the pipe.

主权项

1. An annular ductile iron flange of nominal size, comprising an outer longitudinal surface, a non-threaded inner longitudinal surface, a first basal surface, a second basal surface, and a plurality of circular bolt holes evenly spaced and concentrically located in the first basal surface and connecting the first basal surface to the second basal surface, wherein the improvement comprises:
the inner longitudinal surface defining an inner diameter exceeding an outer diameter of a centrifugally cast length of hubless ductile iron pipe of said nominal size, said pipe also having a nominal thickness and a nominal allowance for casting tolerance, said flange configured to rotate longitudinally around said pipe; and the first basal surface having an annular counterbore adjacent to said inner longitudinal surface, said counterbore having a longitudinal depth equivalent to the sum of said nominal thickness and said nominal allowance and a radial depth equivalent to the sum of between 1.5 and 2.5 times said nominal thickness and said nominal allowance.