Hi:
What are "approved coatings" for buried LPG gas pipe black iron fittings.
The code only alludes to approved, but doesn't specify.
In the Old days, it was 4 layers of 10-mil pipe wrap. but I'm wondering if there is some sort of liquid coating that can be applied (such as alphalt emulsion).
Sure would appreciate suggestions from some of you old-time plumbers out there.
Cheers,