Check valve for use in animal drinker systems

A standpipe assembly, comprising:

• a tube;
• and
• a valve attachable to an end of the tube, the valve comprising:
• a housing defining an inner chamber and having an inlet at a first end of the housing and an outlet at a second end of the housing, the inlet and the outlet providing fluid communication into the inner chamber, wherein a longitudinal axis of the housing extends between the inlet and the outlet;
• a first ball disposed in the inner chamber between the inlet and the outlet and, when the valve is in a vertical orientation with the inlet being at the bottom and the outlet at the top, the first ball rests on a seat extending into the inner chamber from the housing;
• a second ball disposed in the inner chamber between the first ball and the outlet and resting on the first ball when the valve is in the vertical orientation;
• and
• a deflector plate disposed in the inner chamber positioned between the inlet and the first ball and coupled to the housing,
• wherein the first ball, the second ball, and the deflector plate are linearly aligned so that their geometric centers lie on the longitudinal axis,
• wherein the first ball and the second ball are movable from a first position, in which the first ball is resting on the seat and the outlet is open, to a second position, in which the first ball is raised above the seat toward the outlet urging the second ball to engage the outlet and seal the outlet,
• wherein the deflector plate has a monolithic circular concave surface facing the inlet to deflect gas, that enters through the inlet, radially outward and away from the longitudinal axis extending between the inlet and the outlet to prevent the gas from driving the first and second balls upward toward the second position, and
• wherein the deflector plate does not have a flowpath opening therethrough.