1. 1. Boilers, Lined Hot Water Heaters, and Pressure Vessels regulated by the United States Government;
2. 2. Boilers, Lined Hot Water Heaters, and Pressure Vessels operated in private residences or Apartment Complexes of not more than six units; and
3. 3. Boilers, Lined Hot Water Heaters, and Pressure Vessels operated on Indian reservations.

4. 4. A Lined Hot Water Heater that does not exceed any of the following:

   1. a. Heat input of 200,000 BTU/hr;
   2. b. Water temperature of 210° F; or
   3. c. Nominal water containing capacity of 120 gallons.

5. 5. An electric Boiler that does not exceed either of the following:

   1. a. Tank volume of one-and-a-half cubic feet; or
   2. b. MAWP of 100 pounds per square inch or less, with a pressure relief system to prevent excess pressure.

This Article applies to all Boilers, Lined Hot Water Heaters, and Pressure Vessels operated in Arizona, except the following:

Historical Note

Former Rules B-1.1 and B-1.2. Former Section R4-13-401 repealed, new Section R4-13-401 adopted effective April 12, 1979 (Supp. 79-2). Section R4-13-401 repealed, new Section adopted effective April 9, 1992 (Supp. 92-2). R20-5-401 recodified from R4-13-401 (Supp. 95-1). Amended effective October 9, 1998 (Supp. 98-4). Amended by final rulemaking at 15 A.A.R. 1496, effective August 18, 2009 (Supp. 09-3). Amended by final rulemaking at 28 A.A.R. 3952 (December 30, 2022), with an immediate effective date of December 7, 2022 (Supp. 22-4).