Abstract: A liquid fuel vaporizer includes a combustion chamber in which heat is generated by burning fuel therein, an vaporization chamber in which liquid fuel is vaporized by the heat transferred from the combustion chamber to the vaporization chamber. Both chambers are integrally built in a housing, and liquid fuel is supplied from a single injector to both chambers. Liquid fuel consisting of small particles is supplied to the combustion chamber to improve combustion efficiency. Vaporized fuel in the vaporization chamber is prevented from being ignited and burnt therein by various manners, such as intercepting combustion flame, controlling an air/fuel ratio in a range out of a combustible range, or keeping vaporized fuel temperature at a level lower than its self-igniting temperature.

Abstract: The present invention provides a cast steel material for pressure vessels which has improved impact resistance (weldability) and toughness while maintaining its creep rupture strength at a level equal to or higher than the excellent creep rupture strength currently possessed by CrMoV cast steel, as well as a method of making a pressure vessel (or cast steel article) by using this cast steel material which permits a pressure vessel to be made without requiring a material working step such as forging. Specifically, the present invention relates to a cast steel material for pressure vessels which contains C, Si, Mn, Ni, Cr, Mo, V, W, Nb and/or Ta, B, Ti, Al, N, O, P and S in predetermined proportions, the balance being Fe and incidental impurities, provided that the contents of Ti, Al, O and N satisfies the following relationship: N−0.29{Ti−1.5((O−0.89Al)}≦0.

Abstract: A molten steel, which may optionally contain boron to increase hardenability is poured into ingot molds, bloomed and primary hot worked to a mother tube of intermediate cross-section. Before being cooled down to below about 800.degree. C, the mother tube is reheated to about 930.degree. C, scale from the outside surface thereof is removed, and it is secondary hot worked to a pipe of final dimensions with a reduction, measured in terms of equivalent strain as expressed by the following formula, of not less than .epsilon. = 0.02 for the removal of scale from the inside surface of the pipe. It is then directly quenched to produce a finished seamless steel pipe having far better shape at a higher heat efficiency than in the conventional process. Better toughness is effected when the degree of secondary hot work is not smaller than .epsilon. = 0.20..epsilon. = .sqroot.2/3 .sqroot.(.epsilon..sub.1 - .epsilon..sub.2).sup.2 + (.epsilon..sub.2 - .epsilon..sub.3).sup.2 + (.epsilon..sub.3 - .epsilon..sub.1).sup.