Means for testing joints for large diameter pipe

Claim 1

APPARATUS FOR TESTING FOR LEAKS IN A SHORT LENGTH OF LARGE DIAMETER PIPE LINE, SAID APPARATUS COMPRISING A SHORT RIGID METAL CYLINDER HAVING AN OUTER DIAMETER LESS THAN THE INNER DIAMETER OF THE PIPE BEING TESTED, A PAIR OF LATERALLY SPACED RIGID METAL GUIDE FLANGES SECURED TO THE EXTERIOR AND SAID SHORT CYLINDER ADJACENT ONE END THEREOF AND EXTENDING RADIALLY OUTWARDLY THEREFROM AND HAVING A DIAMETER LESS THAN THAT OF THE INNER DIAMETER OF THE PIPE, A SIMILAR PAIR OF GUIDE FLANGES DISPOSED ADJACENT THE OTHER END OF SAID SHORT CYLINDER, A GASKET SYSTEM FOR EACH PAIR OF GUIDE FLANGES, EACH GASKET SYSTEM BEING DISPOSED BETWEEN EACH OF THE GUIDE FLANGES MAKING UP A PAIR, EACH GASKET SYSTEM HAVING A THIN INNER COMPRESSION RING ABOUT WHICH IS DISPOSED A THICK OUTER COMPRESSION RING, THE INNER RING HAVING A NORMAL WIDTH AT LEAST AS GREAT AS THE FLANGE SEPARATION AND BEING OF SOFT, READILY COMPRESSIBLE, FLEXIBLE MATERIAL, THE OUTER RING BEING MASSIVE IN COMPARISON TO THE INNER RING AND NORMALLY HAVING A UNIFORM WIDTH SOMEWHAT LESS THAN THE FLANGE SEPARATION FOR CLEARANCE AND HAVING A THICKNESS WHICH IS SUBSTANTIALLY GREATER THAN THAT OF THE INNER RING, SAID OUTER RING BEING SOLID AND HAVING AT LEAST MOST OF THE OUTER RING BETWEEN GUIDE FLANGES AT ALL TIMES, THE OUTER RING MATERIAL BEING DEFORMABLE, ELASTIC AND SUBSTANTIALLY MORE DENSE THAN THE INNER RING MATERIAL, MEANS FOR SUPPLYING FLUID UNDER PRESSURE INTO THE ANNULAR REGION UNDER THE INNER RING OF EACH GASKET SYSTEM TO FORCE THE INNER GASKET RING INTO SEALING ENGAGEMENT WITH METAL AND EXERT PRESSURE AGAINST THE ADJACENT INNER SURFACE OF THE OUTER GASKET RING, THE FLUID PRESSURE BEING SUFFICIENTLY GREAT TO EXPAND THE OUTER RING IN EACH GASKET SYSTEM SO THAT THE OUTER SURFACE OF EACH OUTER RING IS FORCED AGAINST THE OPPOSED INNER SURFACE OF THE PIPE, THE ONLY UNCONFINED AREA IN THE ENTIRE GASKET SYSTEM BEING A NARROW ANNULAR AREA AT THE FLANGE EDGE ALONG EACH SIDE OF THE OUTER RING, SAID SOLID DENSE OUTER RING, WHEN EXPANDED, ABSORBING ALL THE WORK PERFORMED BY THE FLUID PRESSURE AND STORING SUFFICIENT ENERGY TO PROVIDE POWERFUL RETRACTION BACK TO NORMAL SHAPE UPON RELEASE OF SAID FLUID PRESSURE AND MEANS INDEPENDENT OF THE FIRST NAMED FLUID MEANS FOR CONDUCTING TEST FLUID INTO OR FROM THE ANNULAR TEST CHAMBER LYING BETWEEN THE EXTERIOR SURFACE OF THE SHORT CYLINDER AND OPPOSED INNER SURFACE OF THE PIPE, SAID GASKET SYSTEM PROVIDING FOR MINIMUM VOLUME OF GASKET OPERATING FLUID AND SIMPLE GASKET CONSTRUCTION.