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ASME PTC-1-2015 pdf download

ASME PTC-1-2015 pdf download.General Instructions.
1-1 DEFINITION AND PURPOSE ASME Performance Test Codes (PTCs) provide uni- form rules and procedures for the planning, preparation, execution, and reporting of performance test results. Test results provide numerical characteristics to the per- formance of equipment, systems, and plants being tested. Throughout ASME PTC 1, when the term “equipment” is used with reference to the object of a performance test, it can refer to specific equipment, systems, or to entire plants. 1-2 STANDARDS COMMITTEES ASME PTCs are developed by technical committees that are governed, organized, and appointed by the Performance Test Codes Supervisory Committee under the auspices of the Board on Standardization and Testing. Each code-writing committee is organized to include representatives of several interest groups. The qualifications ofeachmemberofa code-writingcommit- tee are subject to examination and approval by the Supervisory Committee. Members of the code-writing committees are highly qualified, technically competent professionals, generally members of ASME, who have expertise in the field or in an area of expertise needed by the committee, such as special instrumentation. They present their views on matters under consideration as members of a learned profession, not as representatives of employers or special interest groups. 1-3 SCOPE AND ORGANIZATION OF PTCs Most ASME PTCs are applicable to a specified type ofequipment 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 classi- fied into five broad categories. (a) power production (b) combustion and heat transfer (c) fluid handling (d) emission (e) instruments, apparatus, and other supplemental documents 1 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 as compared to design or predicted characteristics, to previous test results, or they can be used to benchmark or ascertain performance at a particular time. Some PTCs are writtenas general documents forrefer- ence in support of the equipment PTCs. These can be considered as technical reference material for the equip- ment codes. Three types of reference codes exist. The first type covers instrumentation used in the mea- surement of thermodynamic or process fluid parame- ters, such as pressure, temperature, flow, and shaft power. Such 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 manda- tory instrumentation requirements contained in the equipmentcodes. Instrumentationinformationinequip- ment test codes supersedes the information given in these supplements, but otherwise these supplements should be incorporated by reference in equipment test codes where deemed appropriate by the committee. The second type covers guidance and reference infor- mation. It currently consists of PTC 1, General Instructions, and PTC 2, Definitions and Values. PTC 2 contains standards for terms, units, values of constants, and technical nomenclature. The third type addresses how to analyze the uncer- tainties associated with measurement of all primary parameters to develop overall test uncertainty. It cur- rently consists of PTC 19.1, Test Uncertainty. Figures 1-3-1 and 1-3-2 show the organization of ASME Performance Test Code categories. 1-4 PHILOSOPHY PTCs provide guidelines for test procedures that yield results of the highest level of accuracy based on current engineering knowledge, taking into account test costs and the value of information obtained from testing. Pre- cision and reliability of test results must underlie all  considerations in the development of an ASME Performance Test Code, consistent with economic con- siderationsas judgedappropriatebyeachtechnicalcom- mittee and in keeping with the philosophy of the ASME Performance Test Codes Supervisory Committee. 1-5 APPLICATIONS OF PTCs Code tests are suitable for use whenever performance must be determined with minimum uncertainty. They are meant specifically for equipment operating in an industrial setting. Typical uses include (a) determining if the equipment meets design or expected performance criteria. (b) incorporating by reference into contracts to serve as a means to determine fulfillment of guarantees. (c) evaluating performance following modification, change in operatingconditions, orany suspected change in performance for which such investigation is required. (d) conducting studies to help determine the value of possible upgrades or modifications to equipment. (e) benchmarking performance, sometimes to help determine the necessity for specific preventive mainte- nance, or possible upgrade or modification. (f) trending performance in time by scheduling per- formance tests at regular intervals. Such trends are also used to help determine necessity for specific preventive maintenance, or possible upgrade or modification. (g) validating results from online or continuous performance-monitoringsystems, which are usuallyless accurate than results of tests conducted in accordance with PTCs. PTCs can be used to quantify the magnitude of per- formance anomalies of equipment that is suspected to be performing poorly or to confirm the need for mainte- nance, ifsimplermeans arenotadequate. PTCs are excel- lent sources or references for simpler routine or special equipment test procedures. Conducting periodic performance tests on equipment can uncover the need for further investigation, which can lead to preventive maintenance or modification. 1-6 TEST UNCERTAINTY 1-6.1 Definition Test uncertainty is an estimate of the limit of error of a test result. It is the interval about a test result that contains the true value with a given probability or level of confidence. It is based on calculations utilizing statis- tics, instrumentation information, calculation proce- dure, and actual test data. ASME PTC 19.1 is the PTC Supplement that covers general procedures for calcula- tion of test uncertainty. PTCs maintain a 95% level of confidence for which uncertainty is calculated as their standard. This confidence level therefore represents a 4 95% chance that the uncertainty interval contains the true value. 1-6.2 Applications of Test Uncertainty Analysis — General Analysis of test uncertainty is useful because it (a) identifies dominant sources of error, their effects on a test result, and estimates of their limits (b) validates quality of test results (c) facilitates communication regarding results (d) facilitates the choice of appropriate and cost-effective measurement devices and procedures (e) reduces the risk of making erroneous decisions (f) demonstrates compliance with test requirements (g) facilitates interpretation of test results 1-6.2.1 Pretest Uncertainty Analysis. PTCs require a pretest uncertainty analysis in order to effectively plan the test. A pretest uncertainty analysis allows corrective action to be taken prior to the test, either to decrease the uncertainty to a level consistent with the overall objective of the test or to reduce the cost of the test while still attaining the objective. 1-6.2.2 Post-Test Uncertainty Analysis. PTCs require a post-test uncertainty analysis to determine the uncertainty intervals for the actual test. This analysis should confirm the pretest systematic and random uncertainty estimates. It serves to either validate the quality of the test results or to expose problems.

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