NEN EN 13648-1 : 2008

Foreword
1 Scope
2 Normative references
3 Terms and definitions and symbols
4 Requirements
  4.1 General
  4.2 Design
      4.2.1 Design temperature
      4.2.2 Drainage
      4.2.3 Stem guiding
      4.2.4 Inserts
      4.2.5 Sublimating cryogens
  4.3 Materials
      4.3.1 General
      4.3.2 Metallic materials
      4.3.3 Corrosion resistance
      4.3.4 Oxygen compatibility
      4.3.5 Acetylene compatibility
      4.3.6 Non-metallic materials
5 Testing
  5.1 Production testing
  5.2 Sample valve tests
      5.2.1 Operating and flow characteristics tests
      5.2.2 Test of the repeatability of leak tightness at
            re-seat
      5.2.3 Cryogenic tests
6 Determination of the certified derated coefficient of
  discharge (K[dr])
7 Cleanliness
8 Marking
9 Sealing
Annex ZA (informative) Clauses of this European Standard
         addressing essential requirements or other provisions
         of EU Directives

Defines the requirements for the design, manufacture and testing of safety valves for cryogenic service, that is to say for operation with cryogenic fluids (as defined in EN 1251-1) below -10 degree C in addition to operation at ambient temperature.