Every blend, pipe and situation can make the length of a pipe different..... In my world.
If the stars are aligned and im not thinking about a sick animal, or tomorrows work load, or any other drama, I can make a coin last maybe 45 minutes. I ALAWAYS want to smoke slowly, but that doesn't always work out.
I prefer larger pipes.....like Lane Era Charatan Make pipes, or Moretti, or even Mario Grande.....so, I sometimes load THREE flakes of something like LNF. That can last me well over two hours. Which is fine with me on the right day. Cooler evening, alone with my NON work thoughts, I try at least 2 or 3 times a week to have one of these times.