Page 118 - QRedition5.0 062021

Quality Requirements Edition 5.0 European Enamel Association

8.6.4 Determination of thermal shock resistance of porcelain and vitreous enamelled 8.6.5 Determination of thermal shock resistance of porcelain and vitreous enamelled
articles in water articles in an air-stream

Purpose and scope Purpose and scope

A lot of enamelled articles are subject to thermal shocks during usage. This specification This specification sheet describes a test procedure to determine the thermal shock
sheet describes the quenching stability which is not to be mixed up with the resistance to resistance of especially heat exchanger panels. (For the thermal shock resistance of
thermal shocks of cooking utensils or other hollowware. The latter applies to DIN ISO 2747. cookware and similar hollowware DIN ISO 2747 is valid).

Test method Test method
Small enamelled articles, cut-outs of utensils or test plates are to be used for this test. Enamelled plates out of production, sized DIN A4, are to be used for testing. They are to
These are to be heated up to the claimed temperature (on air) and immediately after that to be heated up to the required temperature (on air). Following the heating-up phase the test
be quenched ( entirely immersed ) in water of about 15 C. This process is to be repeated plates are to be kept at this temperature for 10 minutes and then cooled down to ambient
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according to the quality requirements. Damage of the enamelling, visible by the naked eye, temperature by an air stream. This testing cycle has to be repeated 5 times. No visual dam-
is not permitted. There are at least three, preferably five samples to be tested. age of the enamelling is permitted.

Test device Test device
No binding regulation No binding regulation

Test temperature Test temperature
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The quenching temperature is a matter of arrangement in each case. For heat exchanger panels a testing temperature of 350 C is valid.

Test report Test report
In the test report to be mentioned: To be mentioned in the test report:
kind and origin of sample kind and origin of test plates
place and date of testing place and date of testing
quenching temperature and number of quenchings testing temperature and number of test cycles

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