Abstract: A pipe adapter flange coupling system for joining two flanged pipe section ends comprises an adapter ring constructed to be positioned between the flanged pipe section ends, a first set of bolts for clamping one flanged pipe section end to one side of the adapter ring, and a second set of bolts for clamping another flanged pipe section end to another side of the adapter ring. The pipe adapter flanged coupling system adapter ring is generally circular and has inner and outer circles of threaded bolt holes. The first set of bolts extending through a compression ring constructed to bear against one flanged pipe section and threadable into the outer ring of bolt holes in the adapter ring. The second set of bolts extendable through another pipe section end and threadable into the inner ring of bolt holes in the adapter ring.