Method of controlling working range of a pump bellows, including maximum limitations such as maximum retracting position and maximum extension position of the bellows, the method comprising the steps of: a) reading at least a first position of a bellows (6', 6") in a closed hydraulic loop volume using at least one position sensor (12', 12"), b) transmitting a first position signal representing the first position to a control system, c) wherein the control system, based on the at least first position signal: c1) determines the position of the bellows (6', 6") represented by the at least first position signal, c2) compares the position of the bellows (6', 6") with a predetermined bellows position operating range, and c3) if the position is outside the predetermined bellows position operating range, instructs an oil management system valve (16', 16") allowing a dual acting pressure boosting liquid partition device to recalibrate the hydraulic fluid volume in the closed hydraulic loop volume to re-establish a hydraulic fluid volume that causes the at least first position to return to a position within the predetermined bellows position operating range, and wherein, - if the position is below the predetermined bellows position operating range, the control system instructs the oil management system valve (16', 16") allowing the dual acting pressure boosting liquid partition device to recalibrate to fill hydraulic fluid into the closed hydraulic loop volume, and - if the position is above the predetermined bellows position operating range, the control system instructs the oil management system valve (16', 16") allowing the dual acting pressure boosting liquid partition device to recalibrate to drain hydraulic fluid from the closed hydraulic loop volume. a) reading at least a first position of a bellows (6', 6") in a closed hydraulic loop volume using at least one position sensor (12', 12"), b) transmitting a first position signal representing the first position to a control system, c) wherein the control system, based on the at least first position signal: c1) determines the position of the bellows (6', 6") represented by the at least first position signal, c2) compares the position of the bellows (6', 6") with a predetermined bellows position operating range, and c3) if the position is outside the predetermined bellows position operating range, instructs an oil management system valve (16', 16") allowing a dual acting pressure boosting liquid partition device to recalibrate the hydraulic fluid volume in the closed hydraulic loop volume to re-establish a hydraulic fluid volume that causes the at least first position to return to a position within the predetermined bellows position operating range, and wherein, - if the position is below the predetermined bellows position operating range, the control system instructs the oil management system valve (16', 16") allowing the dual acting pressure boosting liquid partition device to recalibrate to fill hydraulic fluid into the closed hydraulic loop volume, and - if the position is above the predetermined bellows position operating range, the control system instructs the oil management system valve (16', 16") allowing the dual acting pressure boosting liquid partition device to recalibrate to drain hydraulic fluid from the closed hydraulic loop volume. c1) determines the position of the bellows (6', 6") represented by the at least first position signal, c2) compares the position of the bellows (6', 6") with a predetermined bellows position operating range, and c3) if the position is outside the predetermined bellows position operating range, instructs an oil management system valve (16', 16") allowing a dual acting pressure boosting liquid partition device to recalibrate the hydraulic fluid volume in the closed hydraulic loop volume to re-establish a hydraulic fluid volume that causes the at least first position to return to a position within the predetermined bellows position operating range, and wherein, - if the position is below the predetermined bellows position operating range, the control system instructs the oil management system valve (16', 16") allowing the dual acting pressure boosting liquid partition device to recalibrate to fill hydraulic fluid into the closed hydraulic loop volume, and - if the position is above the predetermined bellows position operating range, the control system instructs the oil management system valve (16', 16") allowing the dual acting pressure boosting liquid partition device to recalibrate to drain hydraulic fluid from the closed hydraulic loop volume. - if the position is below the predetermined bellows position operating range, the control system instructs the oil management system valve (16', 16") allowing the dual acting pressure boosting liquid partition device to recalibrate to fill hydraulic fluid into the closed hydraulic loop volume, and - if the position is above the predetermined bellows position operating range, the control system instructs the oil management system valve (16', 16") allowing the dual acting pressure boosting liquid partition device to recalibrate to drain hydraulic fluid from the closed hydraulic loop volume.