Those blow holes are such a great idea, where they always used because i'm sure i can remember having an alloy bottle that didn't have one. Or maybe i just hadn't noticed it. For those who don't know what they are, they are a hole drilled through the threaded section of the reg that screws into the bottle. If you manage to unscrew the reg while the bottle is presurised, once it is half undone the hole is exposed and harmlessly vents the gas, and alerts you to your error.Originally posted by John C
Because if you dont do it properly you could plug up the blow hole on the threads of your air reg.
And on the subject of manufacturers loctiting the regs onto bottles: Sometimes they do it so strongly that H-pack can't even get it off to re-test your bottles, which is v. annoying as you effectively lose the bottle and reg!