cryogenic vaporizers; ambient forced and natural draft vaporizers for converting cryogenic liquids into gases; cryogenic ambient air natural draft all aluminum vaporizers; diesel fired vaporizers; water pot vaporizers; steam and water heated vaporizer systems comprising a ballast tank, a steam injector, a shell and tube heat exchanger, a water recirculation pump and controls; exhaust gas vaporizers; natural gas fired vaporizer systems comprising a ballast tank, a natural gas fired water heater, a shell and tube heat exchanger, a water recirculation pump and controls; ambient air vaporizers; liquid natural gas (LNG) vaporizers; electric vaporizers; water bath vaporizers; specialized apparatus for the handling, measuring, and controlled dispensing of liquefied gases; separators for filtering and purifying liquefied gases; gas scrubbers; oxygen generators; liquid natural gas (LNG) liquefiers; liquefied gas processing and purification systems sold as a unit, consisting of refrigerators, storage tanks, compressors, pumps, piping, instrumentation; cryogenic processing equipment, namely, distillation columns, flash tanks, piping, and temperature, pressure and flow indicators; closed cycle refrigeration systems comprising compressors, heat exchangers, separators, condensers, receivers, evaporators and controls; cryogenic equipment, namely, cryogenic heat exchangers, vacuum jacketed piping, refrigerators, cooling skids, expansion skids, air treatment modules for liquefied gases, sold separately and as a set; apparatus for the production, application, and maintenance of cryogenic temperatures, namely, vacuum insulated sumps, pipelines, vessels, test chambers and separators, sold separately and as a set; evaporators; distillation and rectification apparatus, not for scientific purposes; heat exchangers; gas absorbers; gas scrubbing columns; pressure reducers, heat exchangers for the evaporation of liquefied gases; hydrogen pressure swing adsorption valve skids; liquid nitrogen based equipment for the cleaning of electronic memory chips and electronic circuit assemblies; gas recycling equipment, namely, piping, vacuum pumps and compressors; gas separation equipment, namely, cryogenic pumps; specialized exotic cryogenic gas storage tanks; high flow liquefied gas vaporization equipment for wind tunnel applications, namely, electrically heated zinc pebble bed vertical vaporizers; small capacity cryogenic storage tanks; hydrocarbon process skids for Ethylene recovery; hydrogen catalytic cracking skids for gasoline processing; industrial gas drying skids for polypropylene gas for plastic component manufacture; gas manufacturing systems comprised primarily of pressure swing adsorption equipment for the recovery, purification and return of gases in industrial applications; solvent recovery systems comprising cryogenic heat exchangers, demisters, separators, knock-out pots, vacuum insulated collector vessels, pumps and controls; pre-treatment modules for air separation plants; nitrogen lens polishing units for the low temperature polishing of cataract lenses; medical oxygen purity samplers