A professional who tends dewatering machines that filter moist solid aluminum hydroxide from coarse slurry. Respnsibilities include:

• Turns valves to regulate flow of slurry and wash water to dewaterers and to admit solids to kilns, according to temperature readings, alumina-quality reports, and discharge rates given by kiln operator.
• Adjusts valves to maintain supply of water for vacuum pumps, wash water, and water-cooled bearings.
• Regulates valves in cooperation with other operators to obtain balancing levels in filtrate tanks, hydrate storage tanks, and hydrate storage overflow tanks.
• Lubricates valves and adjusts packing glands to prevent leaks.
• Changes automatic recording charts in machines.
• Records tank levels and density readings of hydrate in log.
• May tend dust-recovery system.