High pressure fluid control system and method of controlling pressure bias in an end use device

A system for controlling delivery of two variable pressure fluids to maintain a pressure bias between the two fluids within an end use device, the system comprising:

• a. a first fluid supply for supplying a first fluid to the end use device;
• b. a second fluid supply for supplying a second fluid to the end use device;
• c. a pressure regulator disposed in a first fluid supply line between the first fluid supply and the end use device for controlling a first fluid pressure within the end use device as a function of a second fluid pressure within the end use device;
• d. an actively controllable vent valve in fluid communication with the first fluid supply line between the pressure regulator and the end use device;
• e. a first sensor disposed between the pressure regulator and the end use device for measuring pressure in the first fluid supply line;
• and
• f. a second sensor for measuring pressure in a second fluid supply line;
• wherein said actively controllable vent valve is actuatable to an open position to decrease the first fluid pressure within the end use device when a determined pressure differential reversal exceeds a predetermined threshold pressure differential reversal.