O2 fill ratings for cylinders.

[Freeflow]

Apologies if this has been covered before, but if I put a tank into Stoney for O2 cleaning it comes back with a max % O2 sticker on it. I asked and was told it's because the valves will only allow a certain % before Bad Things can happen. Now, as they partial pressure fill, there is 100% going in anyway, but no one else seems to have this restriction.

Anyone any ideas?

[Scuby]

Sounds dodgy to me.

If they're saying something like "O2 clean to a maximum of 40%" or whatever, then they haven't O2 cleaned it properly. If i'm understanding it correctly, they're essentially saying "we take no responsibility if you put O2 through your valve"... but are still more than happy to charge you for O2 cleaning!

As you say, almost everyone uses PP blending, so anything less than 100% certified O2 clean is absolutely useless. Have a word with them. If they aren't able to certify that is is suitable for 100% then demand your money back and go to a reputable company.

Our club use Warwick Scuba, which is about 30mins south of Stoney who seem fairly sensible when it comes to these kind of things.
Personally I use Cormeton, just north of Newcastle - just got a 12l manifolded twinset O2 cleaned with a 32% fill, and a 60% fill in my single 12l for... wait for it... £35.50! I wouldn't like to imagine what Stoney would charge for that!

David

[Tricky]

Originally Posted by Scuby

As you say, almost everyone uses PP blending, so anything less than 100% certified O2 clean is absolutely useless. Have a word with them. If they aren't able to certify that is is suitable for 100% then demand your money back and go to a reputable company.

Spot on. Cylinders and valves are exposed to the highest FO2 at fill time if using PP blending. If you can't put 100% O2 in, the cylinder would be pretty much useless for nitrox.

[Twinsetmad]

I agree...if its cleaned for oxygen service, then its cleaned for use of up to 100%. Stoney usually do this...and its been on the forum before. I live just an hour away from Stoney but won't be taking my gear there to be cleaned...I think they have just found another way to cover thier a*ses.

[asa13]

Does no one in theUK use continuous blending? If not, why not? it's simple, cheap and doesn't need O2 clean tanks.

[nigelH]

Originally Posted by asa13

Does no one in the UK use continuous blending? If not, why not? it's simple, cheap and doesn't need O2 clean tanks.

Because partial pressure filling is simpler and cheaper when people are coming in and asking for specific mixes.