VACUUM HEATING UNITS COMPRISING CAST IRON OR STEEL RECEIVERS, CENTRIFUGAL PUMP AND MOTOR ASSEMBLIES, MULTI-JET VACUUM PRODUCERS, FLOAT SWITCHES, VACUUM SWITCHES, CONTROL PANELS WITH MAGNETIC STARTERS, DISCONNECT SWITCHES, SELECTOR SWITCHES, PILOT LIGHTS ON TRANSFORMERS, INLET STRAINERS, THERMOMETERS, WATER LEVEL GAUGE GLASSES, SUCTION ISOLATION VALVES, COMPOUND AND PRESSURE GAUGES