Disclosed is a pulsation dampening system for high-pressure (e.g., 10K psi and higher) fluid lines. At high fluid flow pressures, the dampening system is a dual stage dampening system, responsive to low (e.g., when first charging the fluid line) and to very high-pressure pulsations. An external containment shell handles the full fluid flow pressures. One or more internal shells contain and handle the internal gas dampening system. The in-flow relationship of the gas dampening component assures that pressure differences between the internal gas handling system and the high-pressure fluid flow is always relatively small. This enables the gas handling components to be constructed of less robust material than the external shell (even though the gas system's internal pressure can equal that of the fluid flow), and be less susceptible to pressure failure.