Differential pressure control for pipless pumping

Claim 1

IN AN INTENSIFIER ASSEMBLY ADAPTED FOR DELIVERING A SMOOTH AND CONTINUOUS FLOW OF COMPRESSIBLE FLUID AT A HIGH DELIVERY PRESSURE HAVING A PLURALITY OF INTENSIFIER UNITS EACH HAVING A HIGH PRESSURE PISTON FACE AND LOW PRESSURE PISTON FACES FOR EFFECTING A COMPRESSION AND RETURN STROKE OF EACH SAID HIGH PRESSUR PISTON FACE, PIPE CONNECTIONS WITH SAID HIGH PRESSURE PISTON FACES FOR DELIVERING A COMPRESSIBLE FLUID AGAINST A BACK PRESSURE DETERMINED BY DEMAND, AND MEANS FOR SUPPLYING SAID COMPRESSIBLE FLUID AT A PRECOMPRESSION PRESSURE TO SAID HIGH PRESSURE PISTON FACES, AND MEANS FOR SUPPLYING A SUBSTANTIALLY NONCOMPRESSIBLE FLUID TO SAID LOW PRESSURE FACES FOR MOVING SAID HIGH PRESSURE FACES PROGRESSIVELY SO THAT ONE HIGH PRESSURE PISTON IS ALWAYS ADVANCING AT A HIGH COMPRESSION DEMAND PRESSURE, WHILE A SECOND HIGH PRESSURE PISTON IS ADVANCED AT A PRECOMPRESSION PRESSURE, AND A THIRD HIGH PRESSURE PISTON IS MOVED IN THE RETURN DIRECTION, THE COMBINATION OF A SOURCE FROM WHICH SAID NONCOMPRESSIBLE PRESSURE FLUID IS SUPPLIED FOR LOADING SAID LOW PRESSURE PISTON FACES AT A DELIVERY PRESSURE WHICH WILL PRODUCE SAID HIGH PRESSURE PISTON FACE DEMAND PRESSURE, A SECOND SOURCE FROM WHICH SAID LOW PRESSURE NONCOMPRESSIBLE FLUID IS SUPPLIED FOR LOADING SAID LOW PRESSURE PISTON FACES AT A LOWER PREDELIVERY PRESSURE, MEANS INCLUDING A SEPARATE SUPPLY LINE TO EACH SAID INTENSIFIER UNIT THROUGH WHICH SAID LOW PRESSURE NONCOMPRESSIBLE FLUID IS SUPPLIED TO THE LOW PRESSURE FACES ASSOCIATED WITH EACH SAID HIGH PRESSURE PISTON FACE, A NONCOMPRESSIBLE FLUID DELIVERY PRESSURE TRANSFER VALVE SHIFTABLE UPON COMPLETION OF THE HIGH PRESSURE COMPRESSION STROKE OF EACH SUCCESSIVE INTENSIFIER UNIT TO CONNECT SAID NONCOMPRESSIBLE FLUID DELIVERY PRESSURE SOURCE WITH THE FLUID PRESSURE SUPPLY LINE TO A SUCCEEDING INTENSIFIER UNIT THEREBY ADVANCING SAID NEXT SUCCEEDING INTENSIFIER UNIT AT SAID HIGH COMPRESSION DEMAND PRESSURE, ONE-WAY CONNECTIONS FROM SAID NONCOMPRESSIBLE FLUID PREDELIVERY PRESSURE SOURCE TO EACH SAID NONCOMPRESSIBLE FLUID PRESSURE SUPPLY LINE FOR CONTINUOUSLY SUPPLYING SAID NONCOMPRESSIBLE FLUID AT SAID PREDELIVERY PRESSURE TO EACH SAID HYDRAULIC FLUID SUPPLY LINE, AND A CONTROL DEVICE OPERABLY UPON COMPLETION OF THE HIGH PRESSURE COMPRESSION STROKE OF EACH SUCCESSIVE INTENSIFIER UNIT TO EFFECT A RETURN MOVEMENT OF SAID INTENSIFIER UNIT AND SIMULTANEOUSLY TO SHIFT SAID NONCOMPRESSIBLE FLUID DELIVERY PRESSURE TRANSFER VALVE TO CONNECT SAID NON-COMPRESSIBLE FLUID DELIVERY SOURCE WITH THE SUPPLY LINE TO A SAID INTENSIFIER UNIT ADVANCING AT SAID PRECOMPRESSION PRESSURE, THEREBY CONTINUING THE ADVANCE OF SAID LAST-MENTIONED INTENSIFIER UNIT AT HIGH COMPRESSION DEMAND PRESSURE.