ASHRAE 158.2 11:2011 Edition

$29.25

ASHRAE-158.2-11

Published By	Publication Date	Number of Pages
ASHRAE	2011	16

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Category: ASHRAE

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4	FOREWORD 1. PURPOSE 2. SCOPE 2.1 This standard applies to refrigerant pressure regulators that meet the definition found in Section 3 and that are intended for refrigerant service in applications where only single-phase flow occurs within the regulator. 2.2 This standard is applicable to refrigerant pressure regulators in the following circumstances: 2.3 This standard specifies procedures, apparatus, and instrumentation that will produce capacity and gradient information with sufficient accuracy to support the proper application of the tested regulator. 2.4 This standard does not do the following: 3. DEFINITIONS AND SYMBOLS 3.1 Definitions
5	3.2 Abbreviations, Acronyms, and Symbols 4. INSTRUMENTATION 4.1 General. Instruments shall have the accuracy listed in this standard and shall be certified standard instruments. 4.2 Temperature-Measuring Instruments 4.3 Pressure-Measuring Instruments 4.4 Fluid Flow-Measuring Instruments7 5. GENERAL PIPING SPECIFICATIONS 5.1 Main Size. The pipe or tubing used for the inlet and outlet connecting mains to the regulator being tested shall be the size and type accommodated by the regulator body connections. The internal surface shall be clean and free of obstructions. 5.2 Main Length. The inlet and outlet mains connected to the regulator being tested shall be straight for a minimum of 14 internal diameters from the face of the regulator inlet and outlet connections. 5.3 Pressure-Tap Holes. Pressure-tap holes shall be located at appropriate points on the circumference of the main. With horizontal mains, the pressure-tap hole position depends on the fluid flowing. For liquids, the pressure-tap holes shall be level…
6	5.4 Fluid Temperature Measurement Locations. Measurement of the temperature of the fluid entering the regulator shall be made at a point located not more than 12 internal main diameters upstream from the face of the inlet connection of the regulator…. 6. DATA TO BE REPORTED 6.1 Test fluid (water or air). 6.2 Regulator setpoint. 6.3 Regulator type (i.e., IPR, OPR, DPR). 6.4 Pressure drop (DP) across the regulator under test. 6.5 Controlled parameter change (CPC, see Figure A-1 in Informative Annex A). 6.6 Inlet pressure and temperature. 6.7 Mass flow rate. 6.8 Descriptive information of the regulator under test, including all of the following that apply: manufacturer’s name and address, model, serial number, regulator size, and connection type and size. 6.9 The date, observer, and pertinent remarks. 6.10 A graph of controlled parameter (CPT) versus mass flow rate (wT) on linear scale, with wT plotted on the ordinate and CPT on the abscissa. All data points for this graph must share the same value of rDP. 7. TEST CONDITIONS 7.1 Water shall be the test fluid used to determine regulator liquid flow capacities. 7.2 Air shall be the test fluid used to determine gaseous or vapor flow capacities. The range of pressure ratios must include air test conditions in both the incompressible (DP/P1 £ 0.1) and compressible (0.1 < DP/P1 £ 0.47) flow regimes to facilit… 7.3 Test fluid and ambient temperatures shall be suitable for the regulator under test. These shall be chosen to ensure that phase change does not occur. 7.4 Inlet pressure shall be adequate to provide the range of pressure ratios and flow regimes at which flow measurements will be made. 7.5 Special care shall be used when testing with water to avoid cavitation or flashing (i.e., water vapor formation) within the test system. 8. TEST PROCEDURE 8.1 Liquid Flow Capacity Test
7	Figure 8-1 Flow test system schematic. TABLE 8-1 Capacity Calculation Methods 8.2 Vapor Flow Capacity Test
8	9. INCOMPRESSIBLE FLOW REGIME CAPACITY CALCULATIONS8,10 9.1 The incompressible flow capacity with other Newtonian fluids and/or at other conditions at the tested gradient (CPCT) and the flow regime may be predicted as follows. 10. COMPRESSIBLE FLOW REGIME CAPACITY CALCULATIONS9,10 10.1 The compressible flow capacity with other gases and/ or at other conditions at the specifically tested gradient (CPCT) and flow regime may be predicted as follows. 11. CHOKED FLOW REGIME CAPACITY CALCULATIONS 12. REFERENCES
9	INFORMATIVE Annex A— Example Tables, Graphs, and Data Sheets TABLE A-1 Example of Preselected Water Flow Test Conditions for Upstream or IPRs TABLE A-2 Example of Preselected Water Flow Test Conditions for Downstream or OPRs
10	TABLE A-3 Example of Preselected Airflow Test Conditions for Downstream or OPRs TABLE A-4 Example of Preselected Airflow Test Conditions for Upstream or IPRs TABLE A-5 Example of Preselected Airflow Test Conditions for DPRs
11	Figure A-1 Example of linear plot of CPT vs. wT test data as required in Section 6.
12	Figure A-2 Example of data sheet for water flow testing.
13	Figure A-3 Example of data sheet for airflow testing.
14	informative Annex B— Example of Computation to Express Regulator Capacity in Terms of Refrigerating Effect