Dual check valve

A dual check valve system, comprising:

• a housing comprising an upper section including a first radial protrusion, an intermediate section including a second radial protrusion, and a lower section, wherein:
• the upper and intermediate sections define a first cavity;
• and
• the intermediate and lower sections define a second cavity;
• a first check valve comprising a first disk configured to engage the first radial protrusion and a second radial protrusion;
• and
• a second check valve comprising a second disk configured to engage the first radial protrusion,
• wherein a diameter of the first radial protrusion is larger than a diameter of the second radial protrusion.

A dual check valve, comprising:

• an upper housing defining an inlet of the check valve, and including a first radial protrusion;
• an intermediate housing coupled to the upper housing and defining a first outlet of the check valve;
• a lower housing coupled to the intermediate housing, and defining a second outlet of the check valve,
• a first cavity interposed between and defined by the upper and intermediate housings for fluidly connecting the inlet and the first outlet;
• a second cavity interposed between and defined by the intermediate and lower housings for fluidly connecting the first and second outlets;
• a first disk mounted in the first cavity to selectively permit fluid flow in a first direction, and prevent fluid backflow in a second direction opposite to the first direction;
• and
• a second disk mounted in the second cavity to selectively permit fluid flow in the first direction, and prevent fluid backflow in the second direction opposite to the first direction,
• wherein when a pressure is applied to place the dual check valve in an open state, a stroke of the second disk is greater than a stroke of the first disk.