High pressure, high flow pump prime valve

This invention relates generally to a pump valve for use in high pressure applications such as advanced controlled vehicle braking systems. The invention is a two-stage, two-poppet prime valve assembly for use in high pressure applications such as vehicle braking systems. The valve assembly has two valve seats and two plungers for allowing the valve assembly to open under high pressure while providing minimal internal flow restrictions to enhance cold temperature and low pressure operation. The two-stage, two poppet valve assembly contains two separate flow paths, one being high pressure, relatively low flow called a stage one, and the other being relatively low pressure, high flow called a stage two. In addition, the valve incorporates a reverse flow bypass feature that is capable of controlling flow at very high pressure and allowing reverse flow with a very low pressure drop.