EN 13786:2004+A1:2008

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

This European Standard defines 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.NOTE1 bar = 105 Pa.Liquefied gases containing methylacetylene and propadiene are not covered by this standard.This European Standard also covers safety devices likely to be fitted onto automatic change over devices. The characteristics of these devices are given in annex A.The requirements of this European Standard generally cover designs where regulation is in one stage, using a single diaphragm. These requirements do not exclude designs using more than one diaphragm, provided that these diaphragms are integrated in a single automatic change over devices complying with the requirements of this European Standard.For specific uses in caravans and leisure vehicles, the automatic change over devices function may also be carried out by an assembly of regulators, forming a "automatic change over devices system" as defined in 3.1.2. This standard covers such an assembly as follows:-special requirements for the manufacture, adjustment and operation of regulators forming a automatic change over devices system, as well as the corresponding test methods are given in annex B;-except for these special requirements, and unless otherwise stated, constructional and performance characteristics given in the body of the standard are also applicable to the devices in annex B.The requirements apply generally to automatic change over device used in locations where the temperature likely to be reached during use is between -20 °C and +50 °C. When the devices are used at temperatures outside this range they shall comply with special requirements defined in annex C.This standard does not include the installation rules