I believe the original had a glass lined tank.
My understanding, Most Water Heaters are ' Glass Lined '
[ I saw that on many a Bradford White Water Heater Boxes during my stint as a Plumber ]
I was told the WH are coated / painted like a washing machine with that enamel or porcelain paint and baked
What does glass lined water heater mean?
In order to protect stainless steel from corrosion, the inner surface of the storage
tank is fused with a layer of processed
glass. The method of application of enamel/
glass-
lining is different from polymer coating, but the objective of both is to prevent corrosion.
In order to avoid corrosion, the inner surface of the storage tanks are coated with a layer of some anti-corrosive material which prevents the surface to get corroded even when it is in contact of warm water. This takes care of the factors which reduce the life of a water heater owing to...
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Different kinds of corrosion protection coatings of storage water heaters in market
Various brands market their products in different ways which is why people get confused between which is what. It happens sometimes that there are two products having the same kind of coating but the names which are used for them by the manufacturers are different, so people think that the two coatings are different from each other, which is not the case in reality.
The major brands of storage water heaters are listed here “Comparison of various brands of Water Heaters/Geysers on BEE star rating in India”. In these brands, the different names of the coatings are as follows:
- Porcelain Enamel Glass Lined Tank
- Glasslined Coated Inner Tank
- Vitreous Enamel Coated Tank
- Blue Silicon Enamel Coated Tank
Moreover, there are a few companies (like AO Smith) which market their products with patented technology of storage tank coating with a different name, but
apart from a few modifications, these all are same.
Apart from the Enamel or Glasslined coating, some manufacturers use Polymer coatings. Polymers are synthetic materials that are applied on top of the metal to protect it from corrosion.