Hi, I’d like to add that these pipe nipples are the perfect way to do two things. One use for them is tying into your glass lined steel tank and the other is for transitioning from one metal to another, like steel plumbing to a brass valve. The plastic lining helps to prevent rusting or corrosion of metals, helping things to last longer and not plug up with corrosion. They are particularly beneficial in hard or softened waters.
Yours, Larry