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ASME PTC 39-2005 pdf download

ASME PTC 39-2005 pdf download.Steam Traps.

2-5 INLET SUBCOOLING The difference between saturated steam temperature corresponding to the inlet pressure and the temperature of the condensate at the steam trap inlet. Inlet subcool- ing may be expressed as degrees Fahrenheit or kelvin. 2-6 SUBCOOLED CONDENSATE The water whose temperature is below the saturated steam temperature. Section 3 Guiding Principles 3-1 ITEMS ON WHICH AGREEMENT SHALL BE REACHED The parties to the test shall reach agreement on the following items prior to conducting the test: (a) object of the test (b) parties to the test (c) test site and date (d) condition of steam and condensate (e) methods of measurement, instrumentation, and equipment to be used ( f) number, size, type, condition, source, inlet and discharge pressures, condensate temperature, and ca- pacities of the steam trap(s) to be tested (g) person who shall be responsible for the test (h) written test procedure, which shall include the data to be taken and recorded to comply with the ob- jective(s) of the test (i) maximum allowable test uncertainty and method of calculating 3-2 QUALIFICATIONS OF PERSON RESPONSIBLE FOR THE TEST The person shall have any or all of the following qual- ifications: (a) registered Professional Engineer (b) a degree from an accredited school of engineering or engineering technology (c) at least two years of experience in the testing of steam traps 3-3 DUTIES OF PERSON RESPONSIBLE FOR THE TEST The person responsible for the test shall ensure that all persons who are involved in the testing perform their duties properly. He/she shall sign and date the test re- sults, thereby certifying, to the best of his/her knowl- edge, their accuracy and that the test was conducted in accordance with the written test procedures. 3-4 PROCEDURES AND TEST APPARATUS Procedures and the arrangement of test apparatus shall be in accordance with Section 4. 3-5 TESTS Sufficient preliminary tests shall be conducted to en- sure that test personnel are completely familiar with test equipment and their respective assignments. Prelimi- nary test shall include the recording of all data neces- sary to the completeness of an actual Code test. 3-6 CALIBRATION OF INSTRUMENTS Each instrument used during the test shall be serial- ized or otherwise identified. Each instrument shall be calibrated in accordance with Section 4. Spare instru- ments, if intended for use during the test, shall also be serialized and calibrated. Records of calibrations shall be available for review by the interested parties at all times. 3-7 DATA SOURCES The properties of steam and water used for calcula- tions shall conform to the latest ASME Steam Tables. 3-8 ADJUSTMENTS DURING TEST No adjustment to the steam trap shall be made dur- ing the test. Following any change or deviations of the test conditions, a sufficient period of time shall be al- lowed to permit the rate of flow, pressure, and temper- ature to attain steady conditions before readings are taken. 3-9 RECORDS AND TEST RESULTS The test records shall include the observations, read- ings, recordings, and instrument calibration records re- quired to attain the test objective(s). Copies of all records shall be furnished to each of the parties to the test. The test report shall conform to the requirements of Section 6. 3-10 CALCULATIONS Calculations may be made using the calculation form provided or may be performed with an equivalent com- puter program or spreadsheet.
4-1 GENERAL If any revisions are made to the methods and guid- ance provided in this Code, the estimation of their ef- fect on test uncertainty shall be made and understood by all parties to the test. This Section presents the mandatory requirements for the instruments, methods, and precautions which shall be employed. The Instru- ment & Apparatus (I&A) Supplements should be con- sulted if sufficient information is not included in this Section. By mutual agreement of the parties to the test, alternative instrumentation or instrument systems, such as flow metering or mass-flow techniques, may be used, provided that such devices or systems have demon- strated accuracy equivalent or greater to that required by this Code. 4-2 CALIBRATION OF INSTRUMENTS AND APPARATUS Instruments and apparatus used for determination under this Code shall be calibrated in accordance with their respective I&A Supplement. 4-3 TEMPERATURE Temperature measurements shall be carried out in ac- cordance with accepted practices and procedures as dis- cussed in the I&A Supplement on Temperature Mea- surement, PTC 19.3. Temperature shall be measured to within ?0.75°F (0.4 K). To meet this accuracy require- ment, temperature shall be measured with resistance thermometers or calibrated thermocouples used with precision reading instruments. Liquid-in-glass ther- mometers may be used for such secondary readings as ambient temperature for manometers and barometers. If liquid-in-glass thermometers are used to measure other variables, they must be calibrated, stem correc- tions must be applied, and graduations must be such that a precision of 0.2°F (0.1 K) is observable. Stagnation thermometer wells shall be used or computed velocity correction applied when the average steam velocity at the sensing point exceeds 300 ft/sec (100 m/s). When the degree of subcooling is 10°F (6 K) or less, the difference shall be measured by differential tem- perature sensing devices as prescribed in PTC 19.3. 4-4 PRESSURE Pressure measurements shall be carried out in accor- dance with the I&A on Pressure Measurement, PTC 19.2. Pressure transmitters, electronic pressure indicators, calibrated elastic gages, or manometers shall be used for reading constant or slowly varying pressures. (a) Manometers shall be of the vertical U-tube or sin- gle leg type with a minimum bore of 5 / 16 in. (8 mm). Spacing between scale graduations shall not be more than 1 / 8 in. (3 mm). In a single leg manometer, means shall be available for adjusting the scale zero while the instrument is in use. Manometers shall be selected such that the scale length and the manometer fluid density permit a reading accuracy to within ?0.5% of the mea- sured pressure or pressure differential. (b) Deadweight gages shall be selected with weights suitable for the pressure range to be measured in ac- cordance with PTC 19.2.

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