a pipe coupling for connecting pipes of the same or different diameters . the coupling has a barrel sleeve with clamping rings on each end . the clamping rings each carry nested seals . an inner portion of each nested seal may be removed so as to adapt the clamping ring to different pipe diameters . each clamping ring is hinged , but becomes iron - bound upon tightening , so that each ring eventually bends as a unitary ring member .