I.S. EN 13786:2004

Foreword
1 Scope
2 Normative references
3 Terms and definitions
  3.1 General terms and definitions
  3.2 Terms and definitions concerning gas
  3.3 Terms and definitions concerning pressures
  3.4 Terms and definitions concerning rates
4 Types of automatic change over devices
  4.1 Introduction
  4.2 Automatic change over devices for installations where
      the final regulator supplies a pressure specified in
      EN 437
  4.3 Other automatic change over devices installation
5 Constructional characteristics
  5.1 General
  5.2 Materials
  5.3 Special requirements
  5.4 Mechanical strength
  5.5 Soundness
  5.6 Mechanical endurance
  5.7 Resistance to humidity changes
  5.8 Resistance to corrosion
6 Performance characteristics
  6.1 General
  6.2 Operational limit characteristics (regulation function)
  6.3 Operational limit characteristics (Change over function)
7 Test methods
  7.1 General conditions
  7.2 Verification of constructional characteristics
  7.3 Verification of performance characteristics
8 Marking, packaging, instructions
  8.1 General
  8.2 Marking of the device
  8.3 Packaging
  8.4 Instructions for use and maintenance
Annex A (normative) Special requirements for automatic
        change over devices fitted with pressure or rate
        operated safety valves
  A.1 Change over devices fitted with an over-pressure relief
  A.2 Automatic change over device fitted with an over-pressure
      shut off safety valve
  A.3 Automatic change over device fitted with an under-pressure
      shut off safety device
  A.4 Automatic change over devices fitted with an excess flow
      valve
  A.5 Automatic change over devices fitted with a regulated
      pressure limiter
Annex B (normative) Special requirements for automatic change
        over devices and automatic change over device systems
        for caravans, motor caravans or fresh water boats
Annex C (normative) Special requirements for low pressure
        automatic change over devices under extreme
        temperature conditions (temperatures below
        -20 degrees C)
Annex D (normative) Method for measuring leaks at test
        pressures less than or equal to 16 bar
  D.1 Scope
  D.2 Diagram of the test
  D.3 Coefficient K
  D.4 Measurement of the leak
  D.5 Checks
Annex E (normative) Complementary test requirements for non
        metallic thermoplastic or thermal setting materials
        used in the construction of automatic change over
        devices
  E.1 Scope
  E.2 Materials
  E.3 Special conditions for carrying out the test mentioned
      in the body of the standard
  E.4 Special requirements
  E.5 Sampling and order of tests
Annex F (normative) Requirements for elastomeric reinforced
        diaphgrams
Annex G (normative) Inlet connections
Annex H (normative) Outlet connections
Annex I (normative) Test method for resistance to corrosion
  I.1 Principle
  I.2 Reagents
  I.3 Apparatus
  I.4 Test method
  I.5 Results
Annex J (normative) Automatic change over device and change
        over device systems for LPG cylinders to supply
        appliances installed in seawater boats
  J.1 Scope
  J.2 General
  J.3 Maximum guaranteed rate
  J.4 Change over device and change over device systems fitted
       with a pressure relief valve
  J.5 Vent
  J.6 Connections
  J.7 Material
  J.8 Resistance to corrosion
  J.9 Marking
  J.10 Instructions for use and maintenance
Annex ZA (informative) Clauses of this European Standard
         addressing essential requirements or other provisions
         of EU Directives
Bibliography

Describes the constructional and operational characteristics, the safety requirements and test methods, and the marking of automatic change over devices with a capacity of less than or equal to 100 kg/h and having a maximum regulated pressure of less than or equal to 4 bar for butane, propane or their mixtures only in the vapour phase.