How does moisture get into a tank?

[Paulo]

A friend on mine (notorious for beig extraordinarily tight) bought a cylinder from another friend of mine (notorious for being extraordinarily risk tolerant). Brought the cylinder for testing and half a L of water poured out. The cylinder is now used by the test centre as the demo for why you need to get cylinders tested.

IMHO the most prolific repeat offenders for water in cylinders are club compressors because dozens of people are using the compressor with varying levels of knowledge and understanding as opposed to shops and personal use where it is usually the same person with a working knowledge of the machine (I expect that this will be dismissed out of hand by some)

[notdeadyet]

I can't remember what I had for breakfast ... 10 years ago no chance

It had a fancy rubber knob on the valve, I don't know anyone that fancy other than one of you lot

[MarkP]

The only time I've ended up with water in my tanks was a result of using a boat's fill whip.

We were all following the "if you need a fill, leave your reg unscrewed" protocol and I'd told the very helpful crew to let me know before they went to fill my tanks*.

It was a very wet weekend and, being helpful, they went ahead and filled mine without telling me and, more importantly, didn't blow our valves dry before screwing in the whip.

The next visual showed a nice spatter pattern of rust from the water in the valves getting blown into the tanks. I suspect all the other divers on the boat enjoyed the same extra sand blasting charge at their next service.


*So I could make sure everything was dry, obvs.

[MarkA]

IMHO the most prolific repeat offenders for water in cylinders are club compressors because dozens of people are using the compressor with varying levels of knowledge and understanding as opposed to shops and personal use where it is usually the same person with a working knowledge of the machine (I expect that this will be dismissed out of hand by some)

I can understand where your coming from. Not long after I started diving, the club rounded up all the new people and did the advanced diver theory lecture. Then the practical lesson with an experienced operator. This was signed off only weeks after getting signed off for novice diver. Me being as keen as mustard spent plenty of time operating the compressor. We got plenty of practice changing the filter as it was only a 2 hour repackable filter.