A shear valve employing a two-stage main poppet valve. The two-stage main poppet valve that can be opened with less force than normally required by prior art designs. For example, if there is pump pressure trapped on the upstream side of the two-stage main poppet valve and little or no pressure or atmospheric pressure on the downstream side, more force than can be provided may be required to open the two-stage main poppet valve to reset the shear valve after the two-stage main poppet valve is closed. The two-stage main poppet valve is designed to first begin to equalize pressure differential across the shear valve without opening a main poppet valve head from its seat inside the shear valve. Thereafter, the main poppet valve head can be opened with less force than otherwise would be required.