How to "O2 clean" regs?

[bada3003]

Hi,

I'll be taking a TDI Deco Procedures course and need to "oxygen service" 1st and 2nd stage regs for use with an AL40 deco cylinder (will be getting new, factory "O2 clean") that will hold high O2 percentage Nitrox. I'm not trying to debate what "oxygen service" means (which seems to be hot button issue for some) but solve a practical problem of prepping 1st and 2nd stage regs for use with deco bottles. That is, as many/some technical divers who maintain their own regs would do on a regular basis when their well-being is on the line. Harlow's book has only brief mention of o-rings (viton preferred) in this context, but little else. Unless I missed it, nothing in Wolfinger's book. If there are good links with relevant info, I would appreciate it.

If there aren't relevant links with actionable solutions, I wonder, based on the bits/pieces I've found, whether the following procedure is what "oxygen service" (an acceptable version thereof) boils down to:

1. For 1st stage: Fully disassemble reg, clean all parts thoroughly (ultrasonic?), dry in minimal dust environment (I don't have a clean room), reassemble wearing latex glove, use christolube mcg111 on dynamic/static o-rings, nitrile o-rings are fine but viton preferred (what about epdm o-rings?). Is there anything I'm missing?

2. For 2nd stage: By default, same as 1st stage. Question: given the lower intermediate pressure, is using the same rigor standard practice in technical diving?

3. What about SPG? Is there such a thing as an "O2 clean" SPG? Or should a new SPG be dedicated just for use with deco cylinder? I understand that even when the cylinder valve is opened slowly, the expanding high O2 gas hitting the SPG generates heat which, if in contact with impurities, might present a combustion danger?

 

[Dr. Lecter]

I have someone who knows what the Hell they're doing O2 clean my 1st stages, and who has the right equipment clean my tanks. I tend to handle O2 cleaning the valves because it's within what I know how to do and have the equipment for. What you describe for the 1st stage is about how I handle my valve cleaning, but do remember not all "O2 compatable" o-rings come "O2 clean." Clean the new o-rings and valve seats, too.

I used to worry about whether my 2d stages were O2 clean, then started diving CCR and realized that since I haven't found an O2 clean toothpaste yet, I should probably stop worrying about it.

The SPG will be seeing high pressure O2, but only very slowly due to the pinhole restriction in the 1st stage HP port. I don't think you need to worry about O2 clean or even O2 dedicated SPGs, but it's your gear and I'm just some guy on the internet.

 

[Jim Lapenta]

It would help if we knew what regs you have. O2 cleaning is not rocket science but there are some mfg's with specific procedures and you need to make sure the service kits are compatible. Some items like the HP seat should not be reused. So unless you have a kit with a new one I would not be tearing the first stage down. Second stages can be cleaned but you are correct that due to the partial pressures are not as critical as the first stage. BUT use Viton o rings and O2 compatible lube.

 

[bada3003]

Thanks. I'm getting a Luxfer AL40 with Thermo Pro DIN/K valve (both factory O2 clean) from divegearexpress, so not worried about cylinder/valve until maintenance time comes around. I have started servicing my own regs hence my focus on getting those adequately O2 serviced. Yes, will clean all parts including o-rings. Not sure I understood the CCR reference but it seems I needn't be too concerned about 2nd stage (beyond good maintenance) and SPG.

---------- Post added April 25th, 2014 at 10:41 PM ----------

I have four cold water (environmentally sealed diaphragms) 1st stages (Hollis DC212, HOG D1, SP MK17, Apek DST), one of which I plan to O2 clean for the deco bottle. I have a service kit for the Apek, so that's the one I'm planning on oxygen servicing. I've found that reusing HP seat can cause IP creep, so am not planning on doing that. I have the 2nd stage that came with the HOG D1 that's been sitting on a shelf (if I remember correctly HOG stated that their regs were 100% O2 clean), so plan on using that with the Apek DST.

It would help if we knew what regs you have. O2 cleaning is not rocket science but there are some mfg's with specific procedures and you need to make sure the service kits are compatible. Some items like the HP seat should not be reused. So unless you have a kit with a new one I would not be tearing the first stage down. Second stages can be cleaned but you are correct that due to the partial pressures are not as critical as the first stage. BUT use Viton o rings and O2 compatible lube.

 

[Scared Silly]

You mention using an ultra-sonic cleaner. O2 cleaning is a two stage process. The first stage is to get rid mineral deposits and other crap via a vinegar/water mixture. The second stage is cleaning via Simple Green Joy/Dawn to remove hydro-carbons. After they are hopefully clean for O2 service.

 

[Bigd2722]

TDI and PSI have classes on 02 cleaning. Both are very good, especially if you service your own rigs

 

[bada3003]

You mention using an ultra-sonic cleaner. O2 cleaning is a two stage process. The first stage is to get rid mineral deposits and other crap via a vinegar/water mixture. The second stage is cleaning via Simple Green Joy/Dawn to remove hydro-carbons. After they are hopefully clean for O2 service.

Thanks. Can I dump everything that came in the Apeks service kit (the packet label specifies "not O2 clean") -- including o-rings, diaphragm, air filter (the air filter has some corrosion/discoloration) -- in water/vinegar solution (ultrasonic), followed by simple green soaking? I plan on rinsing (ultrasonic) using distilled water before O2 clean assembly. Of course, all the metal parts will undergo this process.

---------- Post added April 26th, 2014 at 06:21 PM ----------

TDI and PSI have classes on 02 cleaning. Both are very good, especially if you service your own rigs

Thanks. Unless I'm mistaken, options for such classes in the midwest may be limited. Anyhow, just had to order a pin spanner that fits the Apeks as the ones on the SP multitool doesn't fit.

 

[ams511]

Anyhow, just had to order a pin spanner that fits the Apeks as the ones on the SP multitool doesn't fit.

Not to get too far off track but you may want to give some consideration to standardizing your setups so you do not need to purchase special tools for each regulator and you can also standardize service kits.

BTW, you may want to look at some of the DIY threads regarding Apeks. I remember people saying that two pin spanners make disassembling the regulator easier.

 

[NAM001]

let me add nauii to that list. their course is glas blender and o2 tech. I took my cuorse from the nauii tech director and was very pleased with the skills I left with. and got nitox and trimis gass plending to boot.

TDI and PSI have classes on 02 cleaning. Both are very good, especially if you service your own rigs

 

[docmartin]

Thanks. Can I dump everything that came in the Apeks service kit (the packet label specifies "not O2 clean") -- including o-rings, diaphragm, air filter (the air filter has some corrosion/discoloration) -- in water/vinegar solution (ultrasonic), followed by simple green soaking? I plan on rinsing (ultrasonic) using distilled water before O2 clean assembly. Of course, all the metal parts will undergo this process.

no, don't put non-metal parts in a vinegar solution. simple green or dish washing soap will work for those.