scope:

This standard does not apply to gas utilization equipment:

a. Covered by Part I of the National Fuel Gas Code, ANSI Z223.1-1974;

b. Covered by American National Standard Installation of Domestic Gas Conversion Burners, Z21.8-1971;

c. In boilers complying with American National Standard for Gas-Fired Single Firebox Boilers, Z21.52-1971, and Addenda, Z21.52a- 1973;

d. In boilers complying with American National Standard for Gas-Fired Low-Pressure Steam and Hot Water Boilers, Z21.13-1974;

e. In furnaces such as those of process heaters used in chemical and petroleum manufacture, wherein steam generation is incidental to operation of a processing system; and

f. In situations where loss of steam on boiler shutdown will create a greater safety hazard in an associated process. See Appendix A of American National Standard for Prevention of Furnace Explosions in Natural Gas-Fired Multiple Burner Boiler - Furnaces, Z287.2-1974 (NFPA No. 85B).