scope:

SCOPE AND ORGANIZATION OF PTCs

Most ASME PTCs are applicable to a specified type of equipment defined by the Code. There may be several subcategories of equipment covered by a single code. Types of equipment to which PTCs apply can be classified into the following five broad categories:

(a) power production, energy conversion, and storage

(b) combustion and heat transfer

(c) performance monitoring

(d) fluid handling

(e) emissions

The quantities that characterize performance are defined in each code for the equipment within its scope. Absolute performance characteristics determined by adherence to a PTC can be evaluated and compared to design or predicted characteristics or previous test results, or they can be used to benchmark or ascertain performance at a particular time.

Some PTCs are written as general reference documents in support of the equipment PTCs. These can be considered as technical reference material for the equipment codes. Three types of reference codes exist.

The first type covers guidance and reference information. It currently consists of ASME PTC 2, which contains standards for terms, units, values of constants, and technical nomenclature.

The second type covers instrumentation used in the measurement of thermodynamic or process fluid parameters, such as pressure, temperature, flow, and shaft power. Individual codes referring to process or thermodynamic quantities are known as Performance Test Code Instruments and Apparatus Supplements. They are supplementary to the information on mandatory instrumentation requirements contained in the equipment codes. Instrumentation information in equipment test codes supersedes the information given in these supplements, but otherwise these supplements can be incorporated by reference in equipment test codes where deemed appropriate by the committee.

The third type addresses how to analyze the uncertainties associated with measurement of all primary parameters to develop overall test uncertainty. It currently consists of PTC 19.1.

Over time, the Performance Test Codes Supervisory Committee, under the auspices of the Board on Standardization and Testing, review the PTCs in order to judge their relevancy, technical evolution, development, and applicability, whereby a code may be withdrawn of discontinued.

Figures 1-3-1 and 1-3-2 show the organization of ASME PTC categories. Table 1-3-1 provides a list of withdrawn and discontinued ASME PTCs.