A professional who tends equipment, such as cooking tanks, expellers or presses, driers, grinders, auxiliary pumps, and conveyors, to render and process offal for use as plant and animal foods, performing any combination of following tasks. Respnsibilities include:

• Opens valves and starts pumps and conveyors to move materials through rendering process.
• Observes temperature gauges and rate of flow and condition of materials passing through cookers, expellers, and grinders, and adjusts valves and rate of flow.
• Shovels or dumps guts, bones, and other inedible or condemned parts of slaughtered animals into chute leading to grinder and cooking tanks.
• Drains oil from surface of cooked offal and opens tank discharge to drop cooked material into trough leading to expellers.
• Starts grinding and screening equipment to pulverize and sift tankage, cracklings, and cooked blood for sacking.
• Hangs sack on discharge hopper of screening equipment and opens gate to discharge specified amount of material into sack.
• Ties or sews mouth of sack.
• May be known according to specific work performed as Cooker And Presser; Crackling-Press Operator; Oil-Expeller; Press Operator; Tallow Pumper; Tankage-Grinder Operator; Tank Charger.