No. 844 is a 500°F (260°C), top loading oven from Grieve, currently used for drying water from racks of piston rings at the customer's facility. Workspace dimensions of this oven measure 48" W x 48" L x 36" D. 40 kW are installed in Incoloy-sheathed tubular heating elements, while a 4200 CFM, 3-HP recirculating blower provides horizontal airflow to the workload.

This Grieve oven has 4-inch insulated walls, an aluminized steel exterior and Type 304, 2B finish stainless steel interior with continuously back welded seams. Additional features include an air-operated rear sliding door, reinforced quarter-inch steel plate top and wear bars at sides of workspace. The floor of the workspace is reinforced for 1000 pounds loading at removable subway grate.

Controls on the No. 844 include a digital indicating temperature controller and manual reset excess temperature controller with separate contactors and a recirculating blower airflow safety switch.