gas tank pressure question
I am building a gas tank and here is the question.
I am building it with a petcoc on the bottom and two nipples on the top. One nipple is to fill the tank and is capped and the other nipple is a vent. My question is if I put a check valve (one way valve that lets the air in but won't let the gas/air escape) on the vent line will pressure build up in the tank to the point of it exploding?
I know the vent line is important so that when fuel leaves the tank air comes into the tank to replace the volume that was once the fuel. The check valve seems the like a good way to have the vent line but to keep fuel from spilling out of the vent line.
What do you guys think, is the use of the check valve dangerous? The tank is made of PVC. Thanks in advance guys.