(1) The employer must provide an automatic fire extinguishing system or an automatic dip tank cover for any hardening and tempering tank that uses flammable or combustible liquids and:

(a) Holds five hundred gallons (1893 L) or more of liquid;

(b) Has twenty-five square feet (2.37 m2) or more of liquid surface area.

(2) The employer must prevent fires.

(a) Make sure hardening and tempering tanks are:

(i) Not located on or near combustible flooring;

(ii) Located as far away as practical from furnaces;

(iii) Equipped with noncombustible hoods and vents (or equally effective devices) for venting to the outside.

(b) Treat vent ducts as flues and keep them away from combustible material, particularly roofs.

(3) The employer must make sure air under pressure is not used to:

(a) Fill the tank;

(b) Agitate the liquid in the tank.

(4) The employer must equip each tank with an alarm that will sound when the temperature is within 50°F (10°C) of the liquid's flashpoint (alarm set point).

(5) The employer must make sure a limit switch shuts down conveyors supplying work to the tank when the temperature reaches the alarm setpoint, if operationally practical.

(6) Have a circulating cooling system if the temperature of the liquid can exceed the alarm set point.