BS/EN 12897-2016 pdf download.Water supply – Specification for indirectly heated unvented ( closed ) storage water heaters.
6.1.2 Market surveillance
Storage water heaters are type tested for compliance purposes by means of a specially manufactured unit without the heat exchanger and with an electric immersion heater fitted as specified in B.1 of this standard.
For surveillance check testing of production storage water heaters fitted with heat exchangers, the test may be carried out using either an existing immersion heater or one fitted in an existing connection provided that it meets the positional conditions specified in B.1 and heats at least 85 % of the storage water heaters contents.
In the event of any doubt then the results from the special type test unit shall take precedence.
6.2 Initial type testing
6.2.1 General
Initial type testing shall be performed to show conformity with this European Standard. Tests previously performed in accordance with the provisions of this European Standard (same product. same characteristic(s), test method, sampling procedure, system of attestation of conformity, etc.) may be taken into accouni In addition, initial type testing shall be performed at the beginning of the production of a new product type (unless a member of the same family) or at the beginning of a new method of production (where this may affect the stated properties).
Whenever a change occurs in the product design, the raw material or supplier of the components, or the production process (subject to the definition of a family), which would change significantly one or more of the characteristics, the type tests shall be performed for the appropriate characteristic(s).
6.2.2 Actual volume
The actual volume shall be determined for each model in a manufacturer’s product range using a suitable measuring or calculation technique with an accuracy of± 1 %. This may be done by weighing the heater empty and full of water and calculating the volume of the water. Where a water heater has an internal air space, this test shall be done with the storage water heater at normal maximum inlet pressure, i.e. the set pressure of the pressure-reducing valve.
6.2.3 Rated storage volume
The rated storage volume shall be within the percentage of the actual volume given in Table 1.
6.2.7 Double-walled primary heaters
When a water heater is provided with a double-walled primary heater, drill a (2 ± 0,1) mm hole through the partition wall in contact with the heating side at the most critical location in the primary heater (normally the furthest point from the connections). Fill the primary heater and subject it to a water- pressure of(50 ± 5) kPa. Maintain that pressure for (300 ± 5) s. Water shall emerge to atmosphere from the water heater.
6.2.8 Standing heat loss
The standing heat loss shall be determined in accordance with the procedure given In either:
— Annex B;
— EN 603 79:2004, Clause 14;
— EN 15332:2007,5.4.
6.2.9 Pressure resistance
This test shall be performed on a sample taken from production after lining (where applicable) but before insulation. Connections may be fitted with temporary sealing arrangements. For tank-in-tank water heaters the water side shall be filled to the heat source side maximum inlet pressure before conducting the test on the heat source side.
Raise the internal pressure to 2,0 times the maximum design pressure specified by the manufacturer and maintain the pressure for (600 ± 5) s. There shall be no leakage or cracking of the shell.
6.2.10 Temperature control devices
lithe water heater is supplied with a temperature control device it shall be tested in accordance with the procedure in Annex A.
6.2.11 Heat exchanger pressure drop
The heat exchanger pressure drop shall be tested in accordance with the procedure in Annex A.
6.3 Production testing
Following complete fabrication, but before lining for corrosion protection and application of insulation, each water heater shall meet one olthe following test requirements.
a) Raise the internal pressure to 1,3 times the maximum design pressure specified by the manufacturer using water or another liquid. Hold at this pressure while checking for leakage. Any leakage or cracking shall be deemed a failure and requires remedial action or rejection.BS/EN 12897-2016 pdf download.