1. (1) You must provide an automatic fire extinguishing system or an automatic dip tank cover for any hardening and tempering tank that uses flammable liquids or liquids with flashpoints greater than 199.4°F (93°C) and:

   1. (a) Holds five hundred gallons (1893 L) or more of liquid; or
   2. (b) Has twenty-five square feet (2.37 m²) or more of liquid surface area.

2. (2) Prevent fires.

   1. (a) You must make sure hardening and tempering tanks are:

      1. (i) Not locatedon or near combustible flooring.
      2. (ii) Located as far away as practical from furnaces.
      3. (iii) Equipped with noncombustible hoods and vents (or equally effective devices) for venting to the outside.
   2. (b) You must treat vent ducts as flues and keep them away from combustible material, particularly roofs.

3. (3) You must make sure air under pressure is not used to:

   1. (a) Fill the tank; or
   2. (b) Agitate the liquid in the tank.
4. (4) You 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. (5) You 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. (6) You must have a circulating cooling system if the temperature of the liquid can exceed the alarm set point.

   Note:

   The bottom drain of the tank may be combined with the oil circulating system if the requirements for bottom drains in WAC 296-835-12015 are satisfied.

[Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, and 49.17.060. WSR 17-18-075, § 296-835-13005, filed 9/5/17, effective 10/6/17. Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, 49.17.060 and 29 C.F.R. 1910 Subpart Z. WSR 14-07-086, § 296-835-13005, filed 3/18/14, effective 5/1/14. Statutory Authority: RCW 49.17.010, [49.17].040, and [49.17].050. WSR 02-15-102, § 296-835-13005, filed 7/17/02, effective 10/1/02.]