Patent ID: 7559485

Claim:
A variable orifice valve, comprising: a valve housing that includes an inlet end, an outlet end, and a fluid flow path extending from the inlet end to the outlet end, the fluid flow path including a fixed cross- sectional flow area and a variable cross-sectional flow area; the variable cross-sectional flow area having a first end, a second end, and a wall extending from the first end to the second end, the wall being continuously curved from the first end to the second end so that the cross-sectional flow area increases from the first end to the second end; a moveable, tapered plunger element mounted in the fluid flow path of the valve housing, the tapered plunger element having a first end disposed within the variable cross-sectional flow area, a second end, and an outer surface from the first end to the second end having a linear slope where the tapered plunger element increases in diameter from the first end to the second end in the direction of fluid flow through the fluid flow path; and a thermal spring engaged with the tapered plunger element, the thermal spring being disposed within the fluid flow path whereby the thermal spring is exposed to fluid flowing through the fluid flow path.