ASME PTC 1-2022 pdf download
ASME PTC 1-2022 pdf download.General Instructions.
1-4 PHILOSOPHY PTCs provide guidelines for test procedures that yield results ofthe highest level ofaccuracy based on current engi- neeringknowledge, consideringtestingcosts and the value ofinformation obtained from testing. Code committees, Code users, and parties to the test shall ensure that the philosophy of“unbiased test method” is maintained throughout the designofafairandbalancedtest, wherebythetestis objectiveandwithoutbias towardanyoneparticularinterestgroup. Transparency shall be maintained, whereby all parties to the test are made aware of the goals of the test, technical limitations, challenges, and compromises thatshall be considered when designing, executing, and reportinga testunder theASME PTC guidelines.Precisionandreliabilityoftestresultsshallunderlieallconsiderationsinthedevelopmentofan ASME PTC, consistent with economic considerations as judged appropriate by each technical committee and in keeping with the philosophy of the ASME Performance Test Codes Supervisory Committee. 1-5 APPLICATIONS OF PTCs Code tests are suitable whenever performance shall be determined with minimum uncertainty. Theyare meantspeci- fically for equipment operating in an industrial setting. Typical uses include (a) determining if the equipment meets design or expected performance criteria. (b) being incorporated by reference into contracts to serve to determine fulfillment of guarantees. (c) being incorporated by reference or adopted by governments or government agencies into regulations or laws. (d) evaluatingperformancefollowingmodification,changeinoperatingconditions,oranysuspectedchangeinperfor- mance for which such investigation is required. (e) conducting studies to help determine the value of possible upgrades or modifications to equipment. (f) benchmarking performance, sometimes to help determine the necessity for specific preventive maintenance or possible upgrade or modification.
1-6 TEST UNCERTAINTY 1-6.1 Definition Testuncertaintyis an estimate ofthe limitoferrorofa testresult. Itis the interval ofa testresultthatcontains the true value with a given probabilityor level ofconfidence. Itis based on calculations usingstatistics, instrumentation informa- tion,calculationprocedure,andactualtestdata. ASME PTC 19.1 isthePTC Supplementthatcoversgeneralprocedures for calculation of test uncertainty. PTCs maintain a 95% level of confidence for which uncertainty is calculated as their standard. This confidence level therefore represents a 95% chance thatthe 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 error sources, 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
1-6.2.1 PretestUncertaintyAnalysis. PTCsrequireapretestuncertaintyanalysis, inclusiveofestimates ofsystematic and random errors, in order to effectively plan the test and demonstrate that the test can be designed to meet the Code requirements. Apretestuncertaintyanalysis helps to determine ifthe proposed testmeasurements and the numberand quality ofthe test instruments meet the requirements for compliance with Code. 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 ofthe test or to reduce the cost ofthe test while still attaining the objective. In addition, a pretest uncertainty analysis can be used to determine the significance ofcorrection factors that may be applied to correct test results. PTCs require that the pretest uncertainty analysis includes an analysis ofrandom uncertainties to establish permissible fluc- tuations of key parameters in order to attain allowable uncertainties.
1-6.2.2 Post-Test Uncertainty Analysis. PTCs require a post-test uncertainty analysis to determine the uncertainty intervals for the actual test results. The post-testuncertainty analysis will reveal the quality ofthe testin comparison to the pretestsystematic and random uncertaintyestimates to determine whetherthe allowable testuncertaintydescribed within the Code has been realized. It serves to either validate the quality of the test results or expose problems. 1-6.3 ASME PTC Treatment and Uses of Test Uncertainty Code-writing committees shall state the magnitude of the uncertainties expected in individual measurements and instruct the user in calculation ofuncertainty ofthe final test results. A sample post-test uncertainty analysis based on ASME PTC 19.1 shall be included. This shall include typical random uncertainties based on the experience of the committee. Application oftestuncertaintyanalysis can varybased on the experience ofeach committee and on the manydifferent types of equipment for which Codes are written. There are several acceptable ways to use test uncertainty analysis in ASME PTCs (see paras. 1-6.3.1 and 1-6.3.2). 1-6.3.1 Permissible Uses of Test Uncertainty. The following uses oftest uncertainty are permissible to prepare for and validate the acceptability of a test. One or more shall be used in a single Code.
