A professional who tends furnace, absorber, cooler, scrubber, and auxiliary equipment used in producing phosphoric acid by oxidation and hydration of elemental phosphorus. Respnsibilities include:

• Patrols work area; observes water levels in scrubber, venturi-duct pan, and cooling-tower basin; and reads flowmeter and pressure gauges on phosphorus pump, fans, and blower to verify process conditions.
• Records or calls readings to operator.
• Observes flow of cooling water over top and outer walls of furnace to ensure uniform distribution, and notifies operator of malfunction.
• Takes sample of cooling water for laboratory alkalinity test.
• Turns valves to transfer acid to specified storage tanks and to start and stop water sprays in absorber, as directed, to control acid strength.
• Removes and replaces screens and filters, using wrenches.
• Opens valves to flush phosphorus pump and water-treating equipment with steam and regenerative chemicals.