ISO 4126-7:2013 specifies requirements for safety valves. It contains information which is common to ISO 4126-1 to ISO 4126-6 to avoid unnecessary repetition.
Tämän julkaisun valmistelusta Suomessa vastaa Metalliteollisuuden Standardisointiyhdistys ry, puh. 09 19 231 (vaihde).
Sisällysluettelo
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and units
5 Determination of safety valve performance
5.1 Determination of coefficient of discharge
5.2 Critical and subcritical flow
5.3 Discharge capacity at critical flow
5.4 Discharge capacity for any gas at subcritical flow
5.5 Discharge capacity for non-flashing liquid as the test medium in the turbulent zone where the Reynolds number Re is equal to or greater than 80 000
6 Sizing of safety valves
6.1 General
6.2 Valves for gas or vapour relief
6.3 Calculation of capacity
7 Thermodynamic properties
7.1 Steam data
7.2 Value of C as a function of k
7.3 Theoretical capacity correction factors for sub-critical flow (Kb)
7.4 Estimating chart for compressibility factor, Z
7.5 Capacity correction factor for viscosity, Kv
7.6 Properties of gases
8 Minimum requirements for helical compression springs
8.1 General
8.2 Materials
8.3 Marking
8.4 Dimensions
8.5 Spring plates/buttons
8.6 Inspection, testing and tolerances
9 Minimum requirements for safety valve disc springs
9.1 General
9.2 Materials
9.3 Marking
9.4 Dimensions
9.5 Inspection, testing and tolerances
Annex A Examples of capacity calculations for various media (informative)
5.4 Discharge capacity for any gas at subcritical flow
5.5 Discharge capacity for non-flashing liquid as the test medium in the turbulent zone where the Reynolds number Re is equal to or greater than 80 000
6 Sizing of safety valves
6.1 General
6.2 Valves for gas or vapour relief
6.3 Calculation of capacity
7 Thermodynamic properties
7.1 Steam data
7.2 Value of C as a function of k
7.3 Theoretical capacity correction factors for sub-critical flow (Kb)
7.4 Estimating chart for compressibility factor, Z
7.5 Capacity correction factor for viscosity, Kv
7.6 Properties of gases
8 Minimum requirements for helical compression springs
8.1 General
8.2 Materials
8.3 Marking
8.4 Dimensions
8.5 Spring plates/buttons
8.6 Inspection, testing and tolerances
9 Minimum requirements for safety valve disc springs
9.1 General
9.2 Materials
9.3 Marking
9.4 Dimensions
9.5 Inspection, testing and tolerances
Annex A Examples of capacity calculations for various media (informative)