ASHRAE Standard 158.2 2018
$38.46
ASHRAE Standard 158.2-2018 Methods of Testing Capacity of Refrigerant Pressure Regulators
| Published By | Publication Date | Number of Pages |
| ASHRAE | 2018 | 16 |
This standard (a.) establishes uniform methods of testing for determining the performance of premix and postmix chilled-beverage dispensers that are electrically operated and mechanically refrigerated or ice cooled; (b.) defines the terms used in the methods of testing; and (c.) establishes test conditions for rating.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 1 | ANSI/ASHRAE Standard 158.2-2018 |
| 3 | CONTENTS |
| 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 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 3. DEFINITIONS AND SYMBOLS 3.1 Definitions |
| 5 | 3.2 Abbreviations, Acronyms, and Symbols 3.3 Subscripts 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 Instruments 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 set point. 6.3 Regulator type (i.e., inlet, outlet, or differential pressure). 6.4 Pressure drop DP across the regulator under test. 6.5 Controlled parameter change (CPC) 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 | 8.2 Vapor Flow Capacity Test Figure 8-1 Flow test system schematic. Table 8-1 Methods for Calculating Refrigerant Vapor Flow Capacity 9. INCOMPRESSIBLE FLOW REGIME CAPACITY CALCULATIONS 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: |
| 8 | 10. COMPRESSIBLE FLOW REGIME CAPACITY CALCULATIONS 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. NORMATIVE REFERENCES |
| 9 | INFORMATIVE APPENDIX A—BIBLIOGRAPHY |
| 10 | INFORMATIVE APPENDIX B—EXAMPLE TABLES, DATA SHEETS, AND GRAPHS |
| 11 | Table B-1 Example of Preselected Water Flow Test Conditions for Upstream or IPRs Table B-2 Example of Preselected Water Flow Test Conditions for Downstream or OPRs Table B-3 Example of Preselected Airflow Test Conditions for Downstream or OPRs |
| 12 | Table B-4 Example of Preselected Airflow Test Conditions for Upstream or IPRs Table B-5 Example of Preselected Airflow Test Conditions for DPRs Figure B-1 Example linear plot of CPT vs. WT test data as required in Section 6. |
| 13 | Figure B-2 Example data sheet for water flow testing. Figure B-3 Example data sheet for airflow testing. |
| 14 | INFORMATIVE APPENDIX C—EXAMPLE OF COMPUTATION TO EXPRESS REGULATOR CAPACITY IN TERMS OF REFRIGERATING EFFECT |
