Patent ID: 8028717
Filing Date: 2011-10-04
Classification: F15B,F16K,Y10T

Abstract:
1. A valve system comprising: a body defining an inlet, an outlet, and an exhaust, wherein the inlet is adapted to be coupled to a source of pressurized fluid; a first valve unit including a first exhaust poppet and a first inlet poppet, wherein the first exhaust poppet is movable between an open position for coupling the outlet to the exhaust and a closed position for isolating the outlet from the exhaust, wherein the first inlet poppet is movable between an open position for coupling the outlet to the inlet and a closed position for isolating the outlet from the inlet, wherein the first valve unit is movable to a deactuated position wherein the first inlet poppet is in its closed position and the first exhaust poppet is in its open position; a second valve unit including a second exhaust poppet and a second inlet poppet, wherein the second exhaust poppet is movable between an open position for coupling the outlet to the exhaust and a closed position for isolating the outlet from the exhaust, wherein the second inlet poppet is movable between an open position for coupling the outlet to the inlet and a closed position for isolating the outlet from the inlet, wherein the second valve unit is movable to a deactuated position wherein the second inlet poppet is in its closed position and the second exhaust poppet is in its open position, the valve system being in a faulted state when one of the first and second valve units is in a deactuated position when the other of the first and second valve units is not in a deactuated position; a first crossover passage providing a first flow path between the inlet and the second inlet poppet; a second crossover passage providing a second flow path between the inlet and the first inlet poppet; a first crossover poppet included in the first valve unit for coupling the first crossover passage to the inlet when the first valve unit is not in the deactuated position and decoupling the first crossover passage from the inlet when the first valve unit is in the deactuated position; a second crossover poppet included in the second valve unit for coupling the second crossover passage to the inlet when the second valve unit is not in the deactuated position and decoupling the second crossover passage from the inlet when the second valve unit is in the deactuated position; a first bypass passage coupling the inlet and the first crossover passage, wherein the first bypass passage has a predetermined cross-section to provide a predetermined flow such that when the valve system is in the faulted state and the second valve unit is not in the deactuated position then pressurized fluid passing through the first bypass passage pressurizes the outlet to no more than 1% of the pressure of the source of pressurized fluid; and a second bypass passage coupling the inlet and the second crossover passage, wherein the second bypass passage has a predetermined cross-section to provide a predetermined flow such that when the valve system is in the faulted state and the first valve unit is not in the deactuated position then pressurized fluid passing through the second bypass passage pressurizes the outlet to no more than 1% of the pressure of the source of pressurized fluid.