A dual check valve includes an upper housing, an intermediate housing, and a lower housing, and a first valve seat. The intermediate housing is coupled to the upper housing to define a first cavity, and includes a second valve seat. The lower housing is coupled to the intermediate housing to define a second cavity. A first disk is mounted in the first cavity and configured to selectively contact the first valve seat. A second disk is mounted in the second cavity and configured to selectively contact the second valve seat. When the dual check valve is in an open state, the first disk deflects away from the first valve seat to create a first gap, and the second disk deflects away from the second valve seat to create a second. The first gap is smaller than the second gap.