NOVELTY - Delivering feedstock within a hydrogen-producing pressure range to a hydrogen-producing region of a hydrogen-producing fuel processing assembly (10) involves drawing liquid stream from liquid supply containing carbon-containing feedstock; pumping the liquid stream at least intermittently within/above hydrogen-producing pressure range into outlet conduit; delivering delivery stream; isolating pressure in conduit; and reducing pressure in the outlet conduit during periods in which the liquid stream is not being pumped within or above the hydrogen-producing pressure range.    USE - For delivering feedstock within a hydrogen-producing pressure range to a hydrogen-producing region of a hydrogen-producing fuel processing assembly that is adapted to produce a mixed gas stream containing hydrogen gas as a majority component from it (claimed), which is used in hydrogen- and energy-production industries, including the fuel cell industries.    ADVANTAGE - The method enables reliable delivery of feedstock at variable flow rate, by reducing pressure in an outlet conduit during periods in which the pump assembly is not emitting a liquid outlet stream within or above a hydrogen-producing pressure range, and isolating from pressure in the hydrogen-producing region of the fuel processing assembly and is reduced during periods in which a liquid stream is not being pumped within or above a hydrogen-producing pressure range.    DETAILED DESCRIPTION - Delivering feedstock within a hydrogen-producing pressure range to a hydrogen-producing region of a hydrogen-producing fuel processing assembly (10) that is adapted to produce a mixed gas stream containing hydrogen gas as a majority component from it involves drawing a liquid stream from a liquid supply containing at least one carbon-containing feedstock; pumping the liquid stream at least intermittently within or above the hydrogen-producing pressure range into an outlet conduit; delivering delivery stream containing at least a portion of the liquid stream from the outlet conduit to the hydrogen-producing region; isolating pressure in the outlet conduit from pressure in the hydrogen-producing region during periods in which the liquid stream is not being pumped within or above the hydrogen-producing pressure range; and reducing pressure in the outlet conduit during periods in which the liquid stream is not being pumped within or above the hydrogen-producing pressure range.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram of a fuel processing assembly with a feedstock delivery system.    Hydrogen-producing fuel processing assembly (10)    Hydrogen-producing fuel processor (12)    Feed stream (16)    Hydrogen-producing region (19)    Output stream (20)    Heating assembly (60)    Insulating material (70)