ANSI Z21.13-1991 (R1998)

Scope

1.1.1  This standard applies to newly produced gas-fired low-pressure steam and hot water boilers 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 amd materials, for operation at or below the following pressures and temperatures:

Steam heating boilers - 15 psig (103.42 kPa) steam pressure;

Hot water heating boilers - 160 psig (1.10 MPa) water pressure, 250°F (121°C) water temperature;

Hot water supply boilers - 160 psig (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.

1.1.2  This standard applies to boilers of other than the direct vent type which are categorized according to vent pressure and temperature as either Category I, Category II, Category III or Category IV (see Part IV, Definitions.)

1.1.3  This standard also applies to direct vent boilers (see Part IV, Definitions). A direct vent boiler anticipated by this standard is essentially a balanced flue appliance with the air intake and vent outlet in proximity. Other designs shall be subjected to such additional tests as believed necessary at the descretion of the testing agency.

1.1.4  This standard covers the thermal efficiency and related markings of only those boilers whose efficiencies are not regulated by the Energy Policy and Conservation Act of 1975 and the National Energy Conservation Policy Act of 1978.

1.1.5  This standard applies to a boiler designed for delivery of hot water or for delivery of steam to locations remote from the boiler location.

This standard also applies to a combination boiler and space heater designed to directly provide supplemental heat to the room in which the boiler is installed in addition to providing hot water or steam to locations remote from the room in which the boiler is located.

1.1.6  This standard also applies to a boiler with a draft hood which is factory equipped with an automatic vent damper device (see Part IV, Definitions), hereinafter referred to as vent damper device.

1.1.7  This standard also applies to hot water boilers of other than the direct vent type which are factory equipped with electrically operated or mechanically actuated automatic flue damper devices (see Part IV, Definitions), hereinafter referred to as flue damper devices.

1.1.8  If a value for measurement as given in this standard is followed by an equivalent value in other units, the first stated value is to be regarded as the specification.