Boiling Water Test for Enamel Coating
Boiling water resistance is a very important aspect for measuring the enamel performance of enamel water tanks.
Measuring the loss of the enamelled surface in the boiling water conditions.
Parts to be tested should be prepared as in the following.
a. Test plates should be made of individual metal sheets.
b. The metal sheets used should not be thicker than 2 mm in order to maintain weighing accuracy.
c. The thickness of enamel should be minimum 250 microns and there should not be any surface defects like hole, scars etc.
d. Test parts should be washed by pure water, dried properly by a 100 -110 degrees stove, and cooled in desiccator in order to provide a fix weighing and the first weighing should be made eventually (M1)
2- The test instrument should be prepared in accordance with the DIN ISO 2734 norms as shown in the figure. One of the plates is fixed at the base of the apparatus, while the other one is fixed on the top of the apparatus.
3- The apparatus is filled with pure water up to the 2/3 of its height.
4- The heater is adjusted to yield 2-3 bubble per minute.
5- The corrosion period is minimum 2 days.
6- The plates are removed after the end of corrosion operation and properly washed with 5% acetic acid solution first and then pure water.
7- The plates are dried by a 100 -110 degrees stove, cooled in desiccator and weighed again (M2).
We provide enamel frit and powder for many international electric water heater giants, and have jointly developed a multi-energy enamel formula for water heater system. The weight loss rate of the enamel layer in boiling water test is significantly lower than that of others, which is very suitable for high temperature hot water systems.