You said Teflon coated.
Any concern when using caustic and lifting the Teflon off?
At least that was a claim for PBW and Teflon dishes.
Good point. We have a bunch of teflon encapsulated heaters at work but they are all 'over-the-side' types, so the 'open end' is never submerged. Ours are used for strong nitric acid solutions. They don't look like they are bonded to the element, at least not like a teflon-coated pan. The teflon encapsulated elements look like semi-opaque, white teflon with an almost visible element inside.
For our strong caustic (NaOH) solutions, we just use screw-plug heaters with 304 SS plugs and incoloy elements (that combo covers most applications).
What is the advantage of teflon-encapsulated heaters wrt running the element dry?
Here's a couple of pics of our Electropolishing tank that had orthophosphoric acid in a polypropylene lined tank (actually, it's the melted liner and elements lifted out of the SS tank). This is what happens when someone forgets to turn it off and the temp controller fails (on a weekend) and there is no over-temp protection. The polypro liner melted and floated to the top...and just got 'qued. Those were not teflon-encapsulated but the new ones are.