Patent attributes
A rotary cylinder valve comprises a valve body, a valve cylinder rotationally mounted within the valve body, and first, second, third and fourth valve seats coupled to the valve body. The valve cylinder has a first position in which dual independent flow paths connect the first valve seat with the second valve seat, and connect the third valve seat with the fourth valve seat. The valve cylinder is rotatable to a second position in which the dual independent flow paths connect the first valve seat with the fourth valve seat, and connect the third valve seat with the second valve seat. The valve seats form seals against the valve cylinder, such that no flow path connects the first valve seat with the third valve seat.