This Code provides rules and instructions for conducting performance tests of fuel fired steam generators. These include coal, oil, and gas fired steam generators as well as steam generators fired by other hydrocarbon fuels. The scope also includes steam generators with integral fuel-sulfur capture utilizing chemical sorbents. Steam generators which are not fired by coal, oil, or gas may be tested using the concepts of this Code, but it should be noted that the uncertainty caused by variability of the fuel may be difficult to determine and is likely to be greater than the uncertainties in sampling and analysis of coal, oil, or gas. For example, gas turbine heat recovery and other heat recovery steam generators designed to operate with supplemental firing should be tested in accordance with PTC 4.4. Testing of auxiliary equipment is not addressed in this Code, but are covered PTC 4.2, PTC 4.3 and PTC 11. This Code does not prescribe procedures for testing to determine chemical and physical properties of fuels. This Code specifically addresses equipment used for the generation of steam; however, the basic principles presented are also applicable to other working fluids. Certain types and sizes of equipment used for the recovery of heat released by combustion are not addressed in any specific Performance Test Code. This Code can be used as a general guide in developing performance tests for such equipment; however, such specifically developed performance tests shall not be considered ASME Code tests. This Code provides general procedures for conducting combustible fuel fired steam generator performance tests; however, it cannot possibly provide detailed procedures applicable to every steam generator design variation. Design variations considered in developing this Code include subcritical and supercritical once-through steam generators and oil, gas, stoker, cyclone, pulverized, and fluidized bed firing. For each performance test, a competent engineer must study the actual steam generator and its relation to the remainder of the steam cycle, and develop test procedures which are consistent with this Code. A test report shall be prepared. Many references, which are listed in this Code provide useful supplemental information in planning for a performance test in accordance with this Code.