AIR ENTRAINED PARTICLES CLEANING AND SURFACE TREATMENT MACHINES; GRIT, ABRASIVE, SHOT AND SAND BLASTING MACHINES, SHOT PEENING MACHINES; AND PARTS THEREFOR, NAMELY, BLAST GENERATORS, NOZZLES AND NOZZLE MANIPULATORS, HOSES, BLAST GUNS, FEED CONTROL VALVES, ABRASIVE RECLAIMERS, AND DUST COLLECTOR UNITS