I have received a CO2 cylinder from an online seller fitted with a protective cap over the valve:

I understand these should unscrew, but this one appears to be stuck very firmly. Is there a standard or recommended way to remove these safely? The biggest challenge seems to be securing the cylinder itself to stop it slipping while attempting to turn the cap with a strap wrench or similar. Any tips?


Use two strap wrenches or an equivalent - one on the tank and one on the cap.

You won't crush the tank :)

If you need to make one, then a length of 4*2 and some old car seat belt bolted to one end works well enough - it did when I had to do something similar.

  • $\begingroup$ While you're at it, I'd suggest getting a strap rack that attaches to the wall. Prevents the tank from tipping over while in storage and you can use it to hold the tank while you unscrew the cap. Don't be afraid to use a little muscle opening. Righty tighty lefty loosy $\endgroup$
    – jko
    Jan 7 '20 at 19:11
  • $\begingroup$ Strap wrenches are getting me nowhere unfortunately - even with a 4" breaker bar and enough force to start bending said bar! Would it be safe to use some heat to try to expand the cap? $\endgroup$
    – Riot
    Jan 8 '20 at 20:12

I tried very large strap wrenches, a heat gun, the lot. In the end, nothing short of an angle grinder would do the job.

Be careful with the depth of your cut, to avoid hitting the valve.

I would not try this on any cylinders containing flammable gases or oxygen!

  • $\begingroup$ Holy hell. You're a lot braver than I am. $\endgroup$
    – jko
    Jan 13 '20 at 19:03

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