A special type of pressure regulator installed as part of an accumulator system. Its functions are to direct fluid into the accumulator system, to maintain pressure within set pressure limits, and to unload completely and bypass all fluid flowing in the line from the pump back to the reservoir with no restriction except the resistance offered by the friction of the fluid flowing through the tubing. The valve begins unloading the accumulator system when the accumulator-system pressure drops to the lower limit of the set pressure range. The valve unloads and bypasses the fluid output of the pump back to the reservoir when the accumulator pressure reaches the upper limit of the set pressure range.
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