propane threads

Why are the threads reversed on propane tanks?

So you can’t screw on the wrong type of regulator. I was told that this is because so many men use propane.

      • BBQ tank connectors are reversed because they used to be about the same size as a garden hose, and reversing the threads prevented a lot of non-approved connectors from being attached. Now (in the USA) most have gone to the giant Fisher-Price damage-resistant-threads, so it’s not the issue it once was, but it still prevents lots of wrong things from being hooked up.
  • With welding equipment, usually the fuel tanks all screw on normally and all the oxygen tanks are reversed because confusing the two can have dire consequences (propane is a welding gas also but it comes in a different tank for that). There are adaptors to fit anything to anything though, if you’re stuck with using nonstandard equipment and you feel lucky — a lot of welders have gone to the Big Shop In The Sky while using “cheater” adaptors. - DougC

Not in Canada, DougC. Or in North America, I’m fairly certain. I can’t find a cite to state it explicitly but I think it’s an industry standard that flammable gases have left-hand thread fittings. For an oxy-acetylene torch this not only prevents the obvious hazards of having the wrong gas coming out of the valve you open, but also the oxygen bottle is at a much higher pressure (2000 psi) than acetylene (200 psi).
Also, I’ve used an oxy-propane torch, and the propane bottle was an ordinary one. Had to use a different regulator and cutting tip, though.

      • Well I didn’t go look at mine, but ehhh, what I meant was, “normally”, like as in, ummmm -normally for Austrailia. Yea, that’s it. - DougC