Abstract: Cryogenic vaporization apparatus with multiple ducts each having an inlet to receive cryogenic fluid for vaporization, and an outlet to discharge vaporized fluid to a common discharge collection manifold, there being spaces between the ducts to pass warming fluid, for warming the ducts, and flow restrictors at or proximate the inlets to produce pressure drops in the flow in the ducts, and acting to reduce flow instabilities in the manifold.