scope:

This standard applies to newly produced gas-fired low-pressure steam and hot water boilers with gas inlet pressure ratings not exceeding 0.5 psi (3.5 kPa) and having input ratings of less than 12,500,000 Btu per hour (3 663 389 W) (see Part IV, Definitions), hereinafter referred to as boilers,* constructed entirely of new unused parts and materials, for operation at or below the following pressures and temperatures:

Steam heating boilers

15 psi (103.42 kPa) steam pressure

Hot water heating boilers

160 psi (1.10 MPa) water pressure

250°F (121°C) water temperature Hot water supply boilers 160 psi (1.10 MPa) water pressure 250°F (121°C) water temperature

a. For use with natural gas;

b. For use with manufactured gas;

c. For use with mixed gas;

d. For use with liquefied petroleum gases; and

e. For use with LP gas-air mixtures.

The construction of boilers for use with the above-mentioned gases is covered under Part I.

The performance of boilers for use with the above-mentioned gases is covered under Part II.

* See Exhibit D (D2.1) for boilers covered in Canada that exceed the above limits in gas inlet pressure and/or input ratings.

See Exhibit D, "Items Unique To Canada" for the Canadian method of test to determine combustion efficiency for indoor boilers and the thermal efficiency for both indoor and outdoor boilers.