EN 656:1999/A1:2006

Foreword
1 Scope
2 Normative references
3 Definitions
      3.1 Combustible gases
      3.2 Constituent parts of the boiler
      3.3 Operation of the boiler
      3.4 Country of destination
4 Classification of boilers
      4.1 Gases and categories
      4.2 Classification according to the mode of
             evacuation of the combustion products
      4.3 Type of technologies
5 Constructional requirements
      5.1 General
      5.2 Conversion to different gases
      5.3 Materials and method of construction
      5.4 Design
      5.5 Use and servicing
      5.6 Connections to the gas and water pipes
      5.7 Soundness
      5.8 Supply of combustion air and the evacuation of
             the combustion products
      5.9 Checking the state of operation
      5.10 Drainage
      5.11 Electrical equipment
      5.12 Operational safety in the event of failure of
             the auxiliary energy
      5.13 Adjusting, control and safety devices
      5.14 Burners
      5.15 Pressure test points
      5.16 Chemical composition of the condensate for
             low-temperature boilers
6 Operational requirements
      6.1 General
      6.2 Soundness
      6.3 Nominal, maximum and minimum heat inputs, and
             nominal output
      6.4 Safety of operation
      6.5 Adjusting, control and safety devices
      6.6 Combustion
      6.7 Useful efficiencies
      6.8 Criteria for condensation in the flue for
             standard boilers
      6.9 Resistance of the materials to pressure
      6.10 Hydraulic resistance
      6.11 Combustion air and flue dampers
      6.12 Condensation in a standard boiler
7 Test methods
      7.1 General
      7.2 Soundness
      7.3 Nominal, maximum and minimum heat inputs and
             nominal output
      7.4 Safety of operation
      7.5 Adjusting, control and safety devices
      7.6 Combustion
      7.7 Useful efficiencies
      7.8 Criteria for condensation in the flue
      7.9 Resistance of materials to pressure
      7.10 Hydraulic resistance
      7.11 Combustion air and flue dampers
      7.12 Condensation in a standard boiler
8 Marking and instructions
      8.1 Marking of the boiler
      8.2 Instructions
Annex A (informative) National situations
      A.1 - Categories marked in the various countries
      A.2 - Special categories marketed nationally or locally
      A.3 - Gas groups distributed locally
      A.4 - Boiler supply pressures
      A.5 - Gas connections in common use in the various
            countries
Annex B (normative) Special national conditions
Annex C (informative) A-deviations
Annex D (informative) Practical method of calibrating the
                      test rig to enable the heat loss D[p]
                      to be determined
Annex E (informative) Main symbols and abbreviations used
Annex F (informative) Compilation of test conditions
Annex G (informative) Valving
      G.1 - General
      G.2 - Boilers with permanent ignition burner or
            alternating ignition burner or leakage control
            device or with pre-purge
      G.3 - Boilers without permanent ignition burner or
            alternating ignition burner, without leakage
            control device and without prepurge
Annex H (informative) Determination of the heat losses from
                      the test rig of the indirect method
                      and the contributions of the
                      circulating pump of the test rig
Annex J (informative) Means of determining the ignition time
                      at full rate
Annex K (informative) Example of calculation of the weighting
                      factors for a boiler with several rates
      K.1 - Apportioning of varrho[pi] = 20%
      K.2 - Apportioning of varrho[pi] = 40%
      K.3 - Apportioning of varrho[pi] = 60%
      K.4 - Apportioning of varrho[pi] = 70%
      K.5 - Total apportioning
Annex L (informative) Calculation of conversions of NO[x]
Annex ZA (informative) Clauses of this European standard
                       addressing requirements or provisions
                       of EU Directives