Patent ID: 7089957

Claim:
A valve system for connecting a source to a destination and connecting the destination to a reservoir, comprising: a first valve unit having a first setting and a second setting; and a second valve unit having a first setting and a second setting; wherein the first valve unit and the second valve unit are configured to couple the source to the destination and couple the destination to the reservoir such that: (1) a fluid is allowed to pass from the source to the destination and fluid is prevented from passing from the destination to the reservoir when said first valve unit is in said first setting and said second valve unit is in said first setting; (2) a fluid is allowed to pass from the destination to the reservoir via said second valve unit and fluid is prevented from passing from the source to the destination when said first valve unit is in said first setting and said second valve unit is in said second setting; (3) a fluid is allowed to pass from the destination to the reservoir via said first valve unit and fluid is prevented from passing from the source to the destination when said first valve unit is in said second setting and said second valve unit is in said first setting.