Abstract: Fast-acting valve structure for rapidly evacuating a container of fire retardant material or the like comprising a pilot valve including an annular radially movable, self-centering valve seat, means for actuating the pilot valve either automatically or manually, a poppet valve, structure operably associated with the poppet valve to cause the poppet valve to be biased closed when the poppet valve is in a closed position without mechanical biasing structure, and operable to cause immediate opening of the poppet valve on initial opening of the pilot valve to permit rapid discharge of the container into a discharge manifold through structure for securing the valve structure to the container, and a resiliently mounted and sealed sleeve for guiding the poppet valve between open and closed position.