ASME PTC 25-2001 pdf download.Pressure Relief Devices.
1.3 MEASUREMENT UNCERTAINTY In order to qualify as a valid code test, the total uncertainties of the test, as calculated by the procedures of ASME PTC 1 9.1 , must be equal to or less than the values of maximum acceptable uncertainty. The maximum acceptable uncertainty of the final flow measurement shall not exceed ±2.0% of the measured value and for results other than flow measurements. The maximum acceptable uncertainty shall not exceed ±0.5% of the measured value as determined in accordance with Part I or ±1 .0% of the measured value as determined in accordance with Part II.
1.4 GENERAL 1.4.1 It is assumed that the testing facility has adequate capacity and sufficient pressure to conduct the tests. However, the users of this Code are cau- tioned that the capacity and pressure limitations of the testing facility may restrict the determination of satisfactory operating conditions and other opera- tional features of the pressure relief device.
1.4.2 In addition, field installation and/or abnor- mal operating conditions may adversely affect the function of the pressure relief device. It is not the intent of this Code to attempt to assess the suitability or reliability of the pressure relief device under such conditions. It should also be noted that if the temperature of the medium used to test the pressure relief device differs substantially from the tempera- ture to which the pressure relief device is subjected while in service, the functional characteristics will be different from the test pressures, i.e., opening, closing, blowdown, and bursting pressure. In this case, it is necessary to develop appropriate correc- tions for the pressure relief device under test to account for these differences which is outside the scope of this Code.
1.4.4 The test results shall be reported as mea- sured and calculated. Only tests which comply fully with the mandatory requirements of this Code may be designated as tests conducted in accordance with the ASME Performance Test Code 25. References to other codes, unless otherwise indicated, refer to ASME Performance Test Codes. Should any specific direction in this Code, or any particular measure- ment, differ from those given in other ASME Perform- ance Test Codes for similar measurements, the in- structions of this Code shall prevail.
1.4.6 In some cases, the testing of pressure relief devices may involve the use of high pressure and high temperature fluid. Hazards to personnel will exist unless adequate precautionary measures are taken. Special consideration should be given to adequate design and overpressure protection to the piping system and components, safe discharge from the pressure relief devices undergoing test, and the high noise level usually associated with the discharge of pressure relief devices. The users of this Code should consult the authority having jurisdiction over these safety matters to assure the testing facility meets the minimum mandatory requirements.ASME PTC 25 pdf download.