Batching pig and separation of interfaces in pipe line flow

Claim 1

THE COMBINATION WITH A PIPE LINE FOR TRANSPORT OF SUCCESSIVE FLOWS OF LIQUIDS OF DIFFERENT COMPOSITION HAVING AT LEAST TWO SECTIONS OF DIFFERENT DIAMETER AND AN INTERCONNECTING COUPLING SECTION HAVING AN INTERNAL BORE MERGING WITH THE BORES OF THE ABUTTING ENDS OF SAID SECTIONS, OF A BATCHING PIG DISPOSED IN SAID LINE IN SEPARATING RELATION TO SUCCESSIVE FLOWS AND COMPRISING AN ELASTIC HOLLOW BODY OF SUBSTANTIALLY GREATER LENGTH THAN DIAMETER, THE NORMAL DIAMETER OF SAID BODY WHEN FILLED BEING SUBSTANTIALLY THE SAME AS THE BORE OF THE SECTION OF GREATER DIAMETER, AND A SLOWLY-FLOWING VISCOUS FLUID SEALED WITHIN AND FILLING THE HOLLOW PORTION OF SAID BODY AND SLOWLY MOVABLE WITHIN THE ENCLOSURE UNDER LINE PRESSURE DIRECTED AGAINST THE UPSTREAM END OF SAID BODY WITHOUT RUPTURE OF ITS ENCLOSING SURFACE TO EXTEND OR CONTRACT SAID BODY SO AS TO CONFORM TO THE DIAMETER OF THE BORE THROUGH WHICH SAID PIG IS BEING IMPELLED IN LINEAR MOVEMENT BY SAID LINE PRESSURE.