NEN EN 12897 : 2016

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Requirements
  4.1 Effect of material on water quality and hygiene of
       drinking water
  4.2 Constructional requirements
       4.2.1 Inspection access
       4.2.2 Draining
  4.3 Temperature control
  4.4 Mechanical resistance and stability
       4.4.1 Pressure resistance of water storage vessel
       4.4.2 Pressure resistance of primary heater
       4.4.3 Durability
       4.4.4 Leakage test on double-walled primary heater
  4.5 Safety equipment
       4.5.1 General
       4.5.2 Energy cut-out device
       4.5.3 Temperature relief valve
       4.5.4 Pressure relief/expansion valve
       4.5.5 Pressure reducing valve
       4.5.6 Provision for expansion
       4.5.7 Backflow prevention
  4.6 Temperature display
5 Marking
6 Evaluation of conformity
  6.1 General
  6.2 Initial type testing
       6.2.1 General
       6.2.2 Nominal capacity
       6.2.3 Hot water capacity
       6.2.4 Primary Heating Power (heat exchanger
              performance)
       6.2.5 Durability testing
       6.2.6 Double walled primary heaters
       6.2.7 Standing heat loss
       6.2.8 Pressure resistance
       6.2.9 Temperature control devices
       6.2.10 Heat exchanger pressure drop
  6.3 Production testing
       6.3.1 General
       6.3.2 Pressure resistance
  6.4 Factory production control (FPC)
7 Technical documents
  7.1 General
  7.2 Assembly and maintenance instructions
  7.3 Operating instructions
Annex A (normative) Hot water safety and performance testing
   A.1 Scope
   A.2 Tests required
   A.3 Test apparatus
   A.4 Performance tests
        A.4.1 Hot water performance
        A.4.2 Primary heater pressure drop
   A.5 Interpretation of hot water performance results
        A.5.1 Hot water capacity
        A.5.2 Reheat performance
   A.6 Temperature or temperature pressure relief valve
        function
Annex B (normative) Standing heat loss measurement
   B.1 General
   B.2 Test apparatus
   B.3 Test procedure
   B.4 Calculation of results
Annex C (informative) Inspection access
Bibliography

Defines the constructional and performance requirements and methods of test for indirectly heated, unvented (closed) storage water heaters of up to 2000 l volume suitable for connection to a water supply at a pressure between 0,05 MPa and 1,0 MPa (0,5 bar and 10 bar), and fitted with control and safety devices designed to prevent the temperature of the stored drinking water from reaching 95 degrees C.