If you don't add a vent to those, the constant inflate and deflate of the container will over fatigue the plastic it will start leaking. My next one will have a vent.

Glad to help. ALL of my gas cans have one. Do use the 31/64 drill bit though. Any larger and the vent will leak. Any smaller and you'll never get it in. It's a tight fit.Being these look similar to the good working vents on some of My older cans; I just now ordered this pack to upgrade the newer cans.. I will use a pneumatic drill, rather than an electric, to drill a hole in the fume filled top of those gas cans. Not that I don't care for excitement; but I have some left over fire crackers I would rather use for the boom effect.
The no spill cans are the ONLY ones I'll buy from now on. The spout is that much better than any of the EPA approved spouts.One of my 5 gallon diesel cans is this type, and I like it just fine. I can fill the tank on my tractor without using a funnel and not spill a drop.
Coach
I did the valve stem spout mod but the rubber quickly deteriorated and fell apart.I've read about adding a vent using a valve stem, but I haven't gotten around to doing the modification yet. This doesn't help with the new spout valve issue though.
I need to get one of those. The plastic cans these days are awful.I broke down and bought a safety can. Expensive but awesome. When I need gas I take it on the passenger side floorboard of my car with zero gas smell (if it hasn't been used in a few days). Nice spring-loaded vent in the back.
https://www.amazon.com/dp/B002M3DY9W/?tag=atomicindus08-20
The vent is supposed to stay closed. You only open when pouring.
The real problem is that you are storing your gas improperly if the temp is swinging that much
In California, it is illegal to sell gas containers with the vent hole now; lucky I still have two 5 gallon containers that still have them.
+1 on the Justrite cans. I finally bought one and will never turn back. I need one (2 gal) for mixed gas for my lawn equip. I think gas will last longer in them with the seals. Smell in garage went away. I've bought at least 10 cans over the years. SMH
They make two different caps / spout ring caps. Yellow and black. One is for fine threads the other for coarse. There is also a spacer ring that is needed on some cans to prevent leaks.
Calif is a large state. So they are just trying to cut down on things that cause pollution such as venting tanks and containers. Non venting caps have been around forever. For a few people, no big deal. Add millions and now you have a very serious problem.2 stroke anything is soon if not already gone. We do have to breath !
So instead of a little venting you think it is OK to just spill half a cup of fuel with every pour.
I bought some vent caps and a 31/64 drill bit...problemo solved
I did the valve stem trick to 4 of my cans. Two stems disintegrated and the other two are holding up. I obviously bought 2 different brands. Problem is, I don’t know which brand is holds up. Works really well.
