The following are exempt from installation permits and inspections to the extent stated:

1. (1) Hot water heating boilers below two hundred thousand British thermal units per hour (200,000 Btu/hr) input, except that such objects located in schools, daycare centers, hospitals, and nursing homes shall be inspected;
2. (2) Air tanks in garages and service stations that perform vehicular service or do vehicular repair work as part of daily operations;
3. (3) Air tanks of five cubic feet (5 ft³) capacity (thirty seven and one-half gallons (37.5 gals.)) or less containing two hundred pounds per square inch gauge (200 psig) or less are exempt from inspection and permitting, however tanks above twelve gallons (12 gals.) or one hundred fifty pounds per square inch gauge (150 psig) must be “UM” stamped;
4. (4) Boilers and pressure vessels subject to inspection by the United States Department of Transportation;
5. (5) Boilers and pressure vessels used in private residences and apartment complexes with eight (8) apartments or less;
6. (6) Pressure vessels with six inches (6”) internal diameter or less, with no limit on length of vessel or pressure;
7. (7) Pressure vessels, other than air tanks, with a maximum allowable working pressure of fifteen pounds per square inch (15 psi) or less, or a volume of five cubic feet (5 ft³) or less;
8. (8) Liquefied petroleum gas vessels (propane and butane tanks);
9. (9) Boilers and pressure vessels used in the production, transmission, or storage of oil, natural gas, or casinghead gas (refineries);

10. (10)

    1. (A) Coil-type steam generators that do not have an accumulator drum.

    2. (B) Coil-type hot water boilers where the water can flash into steam when released directly to the atmosphere through a manually operated nozzle may be exempted from this subpart provided the following conditions are met:

       1. (i) There is no drum, header, or other steam space;
       2. (ii) No steam is generated within the coil;
       3. (iii) Tubing outside diameter does not exceed one inch (1”);
       4. (iv) Pipe size does not exceed nominal pipe size three-quarters (3/4);
       5. (v) Nominal water capacity does not exceed six gallons (6 gals.);
       6. (vi) Water temperature does not exceed three hundred fifty degrees Fahrenheit (350° F); and
       7. (vii) Adequate safety relief valves and controls are provided;
11. (11) Fired and unfired water heaters below two hundred thousand British thermal units per hour (200,000 Btu/hr), however, such objects located in schools, daycare centers, hospitals, and nursing homes shall be inspected;

12. (12)

    1. (A) Hot water supply storage tanks.

    2. (B) Tanks which are heated by steam or any other direct or indirect means, when none of the following are exceeded:

       1. (i) Heat input of less than two hundred thousand British thermal units per hour (200,000 Btu/hr);
       2. (ii) Water temperature of less than two hundred ten degrees Fahrenheit (210° F); and
       3. (iii) Nominal water containing capacity of less than one hundred twenty gallons (120 gals.);

13. (13) Pressure vessels which are an integral part of:

    1. (A) Components of rotating or reciprocating mechanical devices and hydraulic or pneumatic cylinders where the primary design considerations and/or stresses are derived from the functional requirements of the device; or
    2. (B) The structure that has a primary function of transporting fluids from one (1) location to another within the system;
14. (14) Vessels with a capacity of one hundred twenty gallons (120 gals.) or less for containing water under pressure, including those containing air, the compression of which serves only as a cushion; and
15. (15) Fired swimming pool heaters, except those in publicly owned swimming pools.