NAC512.566. Exemptions from requirements.

The provisions of NAC 512.500 to 512.594, inclusive, do not apply to:

     1. An unfired pressure vessel that meets the requirements of the United States Department of Transportation for the shipment of liquids or gases under pressure.

     2. An unfired pressure vessel which has an inside diameter that does not exceed 6 inches (152 millimeters).

     3. An unfired pressure vessel used for domestic purposes which contains cold water under pressure, including, without limitation, a vessel containing air, the compression of which serves only as a cushion.

     4. A pressure vessel which contains water heated by steam or by any other means if none of the following limitations is exceeded:

     (a) An input of heat of 199,999 British thermal units per hour (58,600 watts);

     (b) A water temperature of 210 F (99 C); and

     (c) A water capacity of 120 gallons (450 liters).

     5. A fired storage water heater that is directly fired with oil, gas or electricity if none of the following limitations is exceeded:

     (a) An input of heat of 199,999 British thermal units per hour (58,600 watts);

     (b) A water temperature of 210 F (99 C); and

     (c) A water capacity of 120 gallons (450 liters).

     6. An unfired pressure vessel that does not exceed 5 cubic feet in volume and 250 PSIG.

     7. A hot water heater constructed of continuous coils, which is used only to produce steam vapor to clean machinery, equipment and buildings, if:

     (a) The tubing or pipe size does not exceed three-fourths of an inch in diameter and drums and headers are not attached;

     (b) The nominal water containing capacity does not exceed 6 gallons;

     (c) The water temperatures do not exceed 350 F; and

     (d) Steam is not generated within the coil,

Ê except that the provisions of NAC 512.500 to 512.594, inclusive, do apply to safety relief valves on a hot water heater constructed of continuous coils.

     8. An unfired pressure vessel and piping containing liquid petroleum gas and liquid natural gas.

     9. Any vessel, regardless of its size, that has an internal or external operating pressure less than or equal to 15 PSIG.

     10. As used in this section, “fired storage water heater” means a hot water supply boiler used to store or directly supply potable hot water for external use which has:

     (a) A 100 percent makeup; and

     (b) A firing rate of not less than 200,000 British thermal units.

     (Added to NAC by Div. of Industrial Relations by R141-98, eff. 1-28-2000)