Question about hydro testing and o2 cleaning

[cdreamer]

I currently have a customers fiber wrapped O2 bottle used for aviation purposes.
The bottle needs hydro and I need to know if the bottle will need O2 cleaning
before I refill it with pure O2. I've only ever filled O2 for medical cylinders and
I just don't know if hydro testing will contaminate the bottle. Can anyone help
me out with this one? Thanks

 

[mike_s]

have you never seen a bottle (after hydro) and how dirty it is in a hydro facility?


the water used to hydro a tank is not o2 clean. most of the time it's recycled over and over through many tanks and is downright FILTHY.

Chances are they hydro'd a carbon filled fire extingisher with the same water they did your o2 bottle.


yes it needs to be properly o2 cleaned again before use with oxygen service.

 

[cdreamer]

Thanks MiKe!

 

[tbrady]

Hi Terri. We use only fresh water while doing hydrotests. We typically do not O2 clean bottles after the test but it's not that hard to do the bottle right after since it's wet anyway.
Terry Brady Brass Anchor Scuba Frederick MD

 

[NAM001]

Someone refresh my memory can a fiber tank be hydro'd for retur to service. I thought iw was a dead bottle when the hydro expired.

I will have to check my psi book.

 

[rcontrera]

15 years service

 

[Doc Harry]

Someone refresh my memory can a fiber tank be hydro'd for retur to service. I thought iw was a dead bottle when the hydro expired.

I will have to check my psi book.

Yeah, that's my impression, too, deserves a more detailed investigation.

 

[oxyhacker]

Pretty much all the composites have a 15 year life. Also, some of the older ones have a 3 yearr hydro period, though most of them by now have been extended to the standard 5 by the DOT (on the other hand, a few composite tanks have had their exemptions cancelled!).

I would clean it whether it needs it or not. True, the gas industry seems to be pretty cavalier about cleaning O2 tanks after hydro, but then they usually have control over the whole process. In your case, if you probably don't , so since you have no way of knowing how clean the tank is you'd better clean it just so you know. Especially if you are going to be filling it!

 

[akdeepdiver]

To determin the service life, you need to look up and read the Exemption/Special Permit for the cylinder. You can look these up on the DOTs website. It will tell you if it has a 15 year, 20 year, or 30 year service life. (Yes there are a few cylinders out there that have been approved for longer than 15 years.) After you find out the service life, you need to look at the label to determine the date of Manufacture, then do the math.