30mm Air Vent for Camper Van Floor (possible gas dropout vent?)

This is a design for an air hole for the floor of my camper van. The external diameter is 30mm and the tube length is 75mm. I do intend to use this to line a drop-out hole in a gas bottle locker, but I am intentionally not advertising it as a gas dropout vent because I do not know if it meets the necessary safety standards for all countries, so any use of this is done entirely at your own risk.