EN 13136:2013

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols
5 General
6 Pressure relief devices for protection of system
  components
7 Discharge capacities of pressure relief devices
Annex A (normative) - Values of functions, factors and
        properties of refrigerants
Annex B (informative) - Calculation of flow areas for
        non-evaporating and evaporating liquids
Annex C (informative) - Example of calculation for
        sizing pressure relief devices with the
        corresponding pipes
Annex ZA (informative) - Clauses of this European Standard
         addressing essential requirements or other
         provisions of EU Directives
Bibliography

1.1This European Standard describes the calculation of mass flow for sizing pressure relief devices for components of refrigerating systems.NOTEThe term "refrigerating system" used in this European Standard includes heat pumps.1.2This European Standard describes the calculation of discharge capacities for pressure relief valves and other pressure relief devices in refrigerating systems including the necessary data for sizing these when relieving to atmosphere or to components within the system at lower pressure.1.3This European Standard specifies the requirements for selection of pressure relief devices to prevent excessive pressure due to internal and external heat sources, the sources of increasing pressure (e.g. compressor, heaters, etc.) and thermal expansion of trapped liquid. 1.4This European Standard describes the calculation of the pressure loss in the upstream and downstream line of pressure relief valves and other pressure relief devices and includes the necessary data.1.5This European Standard refers to other relevant standards in Clause 5.