System for cleaning pipelines

Claim 1

IN COMBINATION WITH A PIPELINE ADAPTED TO CONTAIN A FLUID FLOWING UNDER PRESSURE AND AT LEAST ONE PIG FOR PASSSAGE THROUGH SAID PIPELINE, APPARATUS FOR INJECTING SAID PIG INTO SAID PIPELINE COMPRISING PIPE MEANS ADAPTED TO CONTAIN SAID PIG CONNECTED AT ONE END TO SAID PIPELINE AND HAVING A DIAMETER ESSENTIALLY THE SAME AS THE DIAMETER OF SAID PIPELINE, THE CONNECTION BETWEEN SAID PIPELINE AND SAID PIPE MEANS HAVING A RADIUS OF CURVATURE SUFFICIENTLY LARGE TO ALLOW SAID PIG TO PASS SMOOTHLY WITHOUT BINDING FROM SAID PIPE MEANS INTO SAID PIPELINE, LAUNCHING CONDUIT MEANS CONNECTING SAID PIPELINE UPSTREAM OF SAID CONNECTION WITH SAID PIPE MEANS BEHIND SAID PIG, LAUNCHING VALVE MEANS IN SAID PIPE MEANS CONDUIT MEANS, DIFFERENTIAL PRESSURE VALVE MEANS IN SAID PIPELINE UPSTREAM OF SAID CONNECTION AND DOWNSTREAM OF SAID LAUNCHING CONDUIT MEANS, AND MEANS FOR SELECTIVELY AND AUTOMATICALLY CONTROLLING OPERATION OF SAID PRESSURE DIFFERENTIAL VALVE MEANS AND SAID LAUNCHING VALVE MEANS SO THAT SAID LAUNCHING VALVE MEANS OPENS AS SAID DIFFERENTIAL PRESSURE VALVE MEANS CLOSES, WHEREBY UPON CLOSURE OF SAID DIFFERENTIAL PRESSURE VALVE PRESSURE FLUID IS PASSES THROUGH SAID LAUNCHING CONDUIT MEANS BEHIND SAID PIG TO FORCE SAID PIG INTO SAID PIPELINE.