Abstract: A method an apparatus for establishing in a system for dispensing fluid in a gaseous phase a predetermined quantify of the fluid in its liquid phase, and for allowing such fluid in its liquid phase to vaporize into its gaseous phase to replace the gaseous phase fluid that is dispensed to users.

Abstract: A steam cleaning system for ridding a workpiece of contaminants by directing a jet of steam onto the workpiece. The system includes a steam generator characterized by a central cavity having walls for containing water fed into it from a water inlet conduit. The steam generator includes a heating element for heating the cavity walls to vaporize water located in proximity to the walls. At least a portion of the cavity walls are provided with a thin porous layer of non-corrodible material to form a surface substantially free of major surface irregularities. The porous layer promotes water vaporization, flashing it into steam. Steam formed in the cavity may be superheated for discharge onto the workpiece through an external nozzle. The system components, including the water pump, are made of non-corrodible, preferably non-lubricated materials to prevent contamination of the workpiece and increase the service life of the pump.