O2 cleaning?

[seeker242]

So I’m going to be enrolling in TDI AN/DP in the near future and have a question about the need for O2 cleaning. I have an AL40 that I use for pony bailout, which I never actually had to use yet. It’s about 8 month old and has had 1 air fill. Going to be using this for deco. I’m assuming I need to have this O2 cleaned?

The regulator I have is scubapro MK25/G250. I bought it used from a guy who used to use it for deco. I just had it serviced at a scuba pro shop but I told them I would just be using it for air. I don’t know if that matters or not? Would I need to have anything additional done with this reg? Not sure.

 

[Wookie]

So I’m going to be enrolling in TDI AN/DP in the near future and have a question about the need for O2 cleaning. I have an AL40 that I use for pony bailout, which I never actually had to use yet. It’s about 8 month old and has had 1 air fill. Going to be using this for deco. I’m assuming I need to have this O2 cleaned?

The regulator I have is scubapro MK25/G250. I bought it used from a guy who used to use it for deco. I just had it serviced at a scuba pro shop but I told them I would just be using it for air. I don’t know if that matters or not? Would I need to have anything additional done with this reg? Not sure.

You don't need to clean the 40 unless you put more than 23.5% O2 in it. That's a snarky way of saying yes, you need to O2 clean the 40. You also need to clean the Mk25. If I'm rebuilding a regulator that I know is for air, I may use silicon on the orings instead of christolube, as a christolube service is $10 more than an air service, and the vast majority of divers don't need or want the extra expense.

The Mk25 O2 ready version is called a Mk25EVO, and contains different repair parts.

 

[chrisch]

What deco gas? For pure O2 then yes probably a clean is sensible. For 50 probably not.

 

[PfcAJ]

Best move is to have all your stuff cleaned appropriately.

I suggest asking the shop how they cleaned/ lubed your reg.

 

[oly5050user]

More than 40% needs to be O2 clean. Tank filled using partial pressure needs to be cleaned. Banked mix, less than 40% no need to clean.

 

[uncfnp]

Hey @seeker242 For your class you will likely be using a higher percent O2 in your deco bottle so yes you will need it O2 clean and labelled as such and appropriate for concentrations greater than 40 percent. It is the same procedure all my tanks get since they are partial pressure blended at one of the Florida shops I use.

I assume you mean to use the MK25 combo for your deco bottle. So again yes to the O2 cleaning, at least for the first stage. The second, as long as they used the appropriate lub as mentioned previously, you should be good to go.

 

[leadduck]

I got it this way, please correct me if wrong: O2 cleaning is most important for the tank and its valve, because here's the highest pressure and strongest flow during filling, and highest risk of accident while filling O2 into a tank with dirty valve and carbohydrates inside from a previous oily air fill. 100% O2 users know it, but also filling EAN with the partial pressure blending method into a dirty tank is very dangerous, so you can't even say that EAN32 is fine, it's only if pre-blended. EAN50 is often filled with the pressure blending method and needs a clean tank.

In the first stage, there's still high pressure but a lot less flow than during tank filling, and lower temperature in the water. In the second stage, flow and intermediate pressure is even lower and it's wet. I've heard of a O2 user burning his lips (greasy lipstick) when breathing O2, but I don't know if there are cases where a second or first stage caught fire under water when breathing EAN50 through a non-O2 clean regulator. Any examples?

 

[KevinNM]

There was an underwater fire mentioned in another thread. IIRC, it was fatal.

The examples of O2 tank fires I've read formal reports on were not while the tank was being filled, it was subsequent to being dropped or knocked over. Except for the aluminum regulator medical gas fires, which is why they banned those.

But basically the aluminum in a tank (or regulator) is the fuel, the 100% is the oxidizer. You just need an ignition source, and the purpose of O2 cleaning is to remove those.

 

[broncobowsher]

Others may disagree, but I only worry about being anal on the O2 cleaning for the tank/valve/1st stage. After that it is relatively low pressure. Been dealing with oxygen (welding) since the 80's. Amazing the abuse and ignorance that people treat O2 with (in the welding field) and how safe it generally is. Besides some intentional fooling around and burning stuff in inappropriate ways the only accidental O2 fire I have ever had was a rigged medical O2 bottle. And there was a whole lot of wrong that led up to that. O2 fire isn't that common, but it can be very bad if it does happen.

 

[PfcAJ]

I've heard anecdotes of regs catching fire on the surface.

Jeez guys just clean your stuff and use o2 grease.