Oxygen Clean Tank Valves

[rddvet]

hi this is what i was clarifying... i had new valves installed on some tanks. and now im getting into Nitrox blending. for the record i certified for that.

so ..... im there using those same valves and tanks. rated 40% nitrox. 6months old. being filled only with air by my own compressor.... This thread i was asking, since the 40% Nitrox valves have o-rings that are viton... can i wash them with simply green and regrease everything with o2 compliant grease..... so i can do PP blending on this tank

what do you mean pumping OCA?

No cleaning? well.... just wana be thorough... or be sure.... that the last person who installed the valve could have used silicon grease on the neck o ring....

Not to be rude but if you’re a certified gas blender and you don’t know the answers to the questions you’re asking then your course was exceptionally lacking. This is all part of a good quality blender course.

 

[J-Vo]

Side question, is it big explosions that we're primarily concerned with when dealing with O2 or are we worried that there will be small scale combustion in the cylinder/valve that puts high CO in our breathing gas?

I have had a valve seat toast while boosting O2. Ended up with a valve that woulda close and some rank smelling O2 leaking out.

 

[J-Vo]

DGX sells valve O2 conversion kits:

DGX Handwheel for SCUBA Valves

The DGX Handwheel for SCUBA valves make it easy to open or close the valve even while wearing gloves.

www.divegearexpress.com

 

[Jersey1971]

I have had a valve seat toast while boosting O2. Ended up with a valve that woulda close and some rank smelling O2 leaking out.

Did you figure out the root cause of the toasting? Fill too fast? Dirty valve? Bad O2 supply?

To reiterate my somewhat tongue in cheek previous question, is the consensus that transfilling an O2 clean setup with air or lean nitrox with a standard whip doesn't disqualify that tank/valve from future O2 use? Does anyone use a dedicated "O2 clean" whip?

 

[boulderjohn]

Or do people have fancy compressors when nitrox filling?

The local dive shop provided only air, and it wanted to change that, so their manager took gas blending course from me. We talked about oxygen compatible air, and the course's text listed the specifications for normal grade E air and oxygen compatible air. (There is surprisingly little difference.) He produced the shop's last evaluation, and it showed they were well above the standard for oxygen compatible air. They weren't doing anything special. I would bet that it is pretty common for dive shops to be pumping oxygen compatible air without knowing it.

 

[rddvet]

I would bet that it is pretty common for dive shops to be pumping oxygen compatible air without knowing it.

It's exceptionally easy with a properly maintained compressor, a good filter, and especially if it has low use.
My home compressor has never produced anything other that OCA and all I use is a prepacked Lawrence Factor filter. I actually did a little test and let one go 27 months during a period I wasn't diving much and the gas still tested OCA.

 

[Superlyte27]

The local dive shop provided only air, and it wanted to change that, so their manager took gas blending course from me. We talked about oxygen compatible air, and the course's text listed the specifications for normal grade E air and oxygen compatible air. (There is surprisingly little difference.) He produced the shop's last evaluation, and it showed they were well above the standard for oxygen compatible air. They weren't doing anything special. I would bet that it is pretty common for dive shops to be pumping oxygen compatible air without knowing it.

The reverse is also true. Dive shops are pumping unsafe air without knowing it.

 

[nadwidny]

The local dive shop provided only air, and it wanted to change that, so their manager took gas blending course from me. We talked about oxygen compatible air, and the course's text listed the specifications for normal grade E air and oxygen compatible air. (There is surprisingly little difference.) He produced the shop's last evaluation, and it showed they were well above the standard for oxygen compatible air. They weren't doing anything special. I would bet that it is pretty common for dive shops to be pumping oxygen compatible air without knowing it.

When I worked in an air testing lab (ok, full disclosure I owned the place) pretty much every compressor from every fire hall, scuba shop, or oil field SCBA fill station, met and exceeded OCA standards without anything other than the filtration that came with the unit. Of the thousands of tests I ran maybe 3 or 4 didn't meet OCA requirements.

 

[J-Vo]

Did you figure out the root cause of the toasting? Fill too fast? Dirty valve? Bad O2 supply?

Not sure. I cleaned the valve, but I think maybe the seat was some incomparable material. It was literally some old valve I had on the shelf for years before slapping it on an AL19 I was planning to use for surface O2.

 

[jeffmg]

The reverse is also true. Dive shops are pumping unsafe air without knowing it.

A shop that doesn’t get at the very least an annual test shouldn’t be operating imo

We had one in my town a number of years ago that was found operating with terrible results

They’re out of business now but there is no oversight or regulation for dive shop air quality