Patent ID: 8074678

Claim:
A reversible flow valve with a first inlet/outlet and second inlet/outlet configured for fluid flow in either direction; the reversible flow valve comprising: a valve chamber having a lower wall with a first valve port opening and a second valve port opening in communication with a first inlet/outlet and a second inlet/outlet of the valve, respectively; a shaft rotatably disposed in the valve chamber in a generally vertical orientation; an inner modulating disk rotatably coupled to the shaft, the inner modulating disk disposed in the valve chamber over the first valve port opening, and having at least a first tapered semi-circular slot that is aligned with the first valve port opening, where the inner modulating disk is configured to rotate from a closed position, in which the inner modulating disk is positioned over the first valve port opening, to an open position in which rotation of the inner modulating disk adjustably positions a wider or narrower portion of the first tapered semi-circular slot over the first valve port opening, to adjustably vary the rate of fluid flow through the first valve port opening and the first tapered semi-circular slot, the inner modulating disk being configured to be movable in an axial direction towards and away from the first valve port opening; an outer modulating disk encircling the inner modulating disk, the outer modulating disk disposed in the valve chamber over the second valve port opening, and having a second tapered semi-circular slot that is aligned with the second valve port opening, the outer modulating disk being configured to rotate with the inner modulating disk from a closed position, in which the outer modulating disk is positioned over the second valve port opening, to an open position in which rotation of the outer modulating disk adjustably positions a wider or narrower portion of the second tapered semi-circular slot over the second valve port opening, to adjustably vary the rate of fluid flow through the second valve port opening and the second tapered semi-circular slot, the outer modulating disk being configured to be movable in an axial direction towards and away from the second valve port opening; wherein the inner modulating disk in the closed position is configured to move away from the first valve port opening, and the outer modulating disk in the closed position is configured to move against the second valve port opening, to thereby resist fluid flow through the second valve port opening; and wherein the outer modulating disk in the closed position is configured to move away from the second valve port opening, and the inner modulating disk in the closed position is configured to move against the first valve port opening, to thereby resist fluid flow through the first valve port opening.