Energy saving downhole and subsea valve

A pressure operated wellbore valve, comprising:

• a valve body having a bore therein for a shuttle, the shuttle comprising a piston having a longitudinal flow port for a power fluid to move through the shuttle longitudinally, the valve body comprising a power fluid inlet port at one longitudinal end and a power fluid flow port at another longitudinal end;
• a biasing device disposed in a chamber on one side of the shuttle;
• and
• wherein the shuttle comprises a first seal proximate the power fluid inlet port in the valve body such that when the biasing device urges the shuttle to one end of the bore, the power fluid is in communication between the power fluid inlet and the power fluid flow port, and wherein when a pressure of the power fluid at the power fluid inlet port urges the shuttle away from the power fluid inlet port, the first seal stops flow of the power fluid through the shuttle, and wherein a second seal between the shuttle and the bore is opened such that a flow path between the power fluid flow port and the exterior of the valve body is opened.