The flash tank and three slurry tanks are located in a tank farm adjacent to the Tedlarmanufacturing building. The slurry tanks are 11 feet in diameter, 19 feet tall, and have acapacity of 10,800 gallons (Figure 2). The tank shell and top are one-quarter inch thickstainless steel. Each tank top has a hinged, unsealed steel cover on a 24-inch diametermanway and a large agitator motor drive and gearbox5. The agitator assembly is bolted tostructural steel beams that are welded directly to the tank top.The slurry tank feed and drain lines are equipped with isolation valves. The slurry tankshave a common overflow line attached near the top of the tanks. Blind flanges are installedon the overflow line and isolate one tank from another if one or two tanks are operatingwhile the third is undergoing maintenance.The 3-foot diameter flash tank vents small concentrations of flammable vapor directly intothe ambient atmosphere, so the area is equipped with a flammable vapor air monitoringdevices to notify personnel when explosion hazards are present. The continuous air monitors are located on the catwalk near slurry tank 3 and on the flash tank vent pipe (Figure3). An alarm in the Tedlar control room activates if either device detects flammable vaporabove the instrument set point