DIN first stages, the reality - they get water in 'em.

[drbill]

I worry more (perhaps wrongly so) about the water that gets trapped inside the threads of the tank valve before I put the reg on. I do use short bursts of air from the tank to blow it out as much as possible, and also keep my DIN cap on as much as possible.

 

[fdog]

Dave, you might also consider a DIN plug. Most folks who own DIN valved cylinders use these plugs.

All the best, James

 

[undrwater]

DIN plugs and caps don't answer the question as I see it. Post dive, there is a lot of moisture hanging around the tank fittings. When the DIN is unscrewed, the fear is that the moisture in the general area will get into the hole.

Have I got this right?

I worry a bit too, but I towel dry the whole area before unscrewing. What if I don't have that luxury (dive boat?), is there a possible concern?

 

[Aquanautchuck]

After every dive this is what I do. Bleed down system, then remove first stage. After I get it off the tank I make sure I keep it face down, take the screw on cap and blow any water out of it from the tank, blow some air on the threads of the 1st stage then put cap on. At home I rinse regs with caps on in fresh water, wipe the reg down, remove caps and hang to dry. In 9 years of use only once have gotten salt water in my reg and that time I did not tighten the cap on the first stage. It seems to work for me. If you do not want to blow the threads off then just wipe off with a towel.

Charles

 

[Mambo Dave]

Wow, I had no clue this thread continued - my e-mail notification seems to have gone ka-put. :11:

Looks like a few are at least seeing the possibility of it happening.

Aquanautchuck, I think we're mostly talking about between-dive change-overs here, not for a single dive, then put it all away nicely, situation.

drbill, your point is a good one. Are you worried about the water working its way down into a tank?

funkyspelunker, thank you for that - I had a feeling people who really knew first stages (i.e. those who worked on them) were doing this.

undrwater, is it a possible concern? Well, that is the crux of the matter. I had some theories before I started this thread.

1.) While we've all heard of the horrors salt water, or any water, can to if allowed into a first stage, I have this feeling that some first stage internals actually handle the minute amounts of water (equivalent to condensation, if that) better than others. And that first stages have probably become more robust at handing it over the years.
2.) And that there were people out there who had quick and dirty (or ‘clean’) ways to flush a first stage out instead of tearing the thing down, or taking it to a LDS to have it serviced (of course, some LDS’s will probably always want you to bring in your first stage).
3.) And, lastly, that it probably isn’t that big of a deal. It happens, and I have a feeling it happens a little more than some may have noticed, but the small amount doesn’t affect most systems enough to bring them to failure.

That being said, I have a dive buddy who has a Poseidon reg. In his DIN neck is a metal screen filter (like a lot of first stages have I guess). His, however, seems to be made of brass, and is highly corroded with green oxidation. This brass filter seems like it could corrode to extents that would limit his air intake. Our question was if sea water exposure speeds up the corrosion of Poseidon inlet filters, or even if what we’re seeing is what we think we’re seeing. Maybe it wasn’t brass, isn’t corroded, and was greenish all along, lol?

Some first stages are going to handle sea water better than others. For thosee of us who end up in fast and dirty change-over situations (dive boats, shore dives, etc.) it would be nice to hear from engineers who design and/or regularly work on the first stages. Maybe some really are better for sea water than others, despite what companies try to sell us?

 

[fdog]

Dave, although it is a small sample (thus not statistically indicative of anything), here's my experience:

> I use exclusively DIN.
> I put in about 200 dives per year.
> 80% Salt water.
> About 70% on a boat, with cylinder changes.
> No special treatment (freshwater rinse) during changes. No air blasting. No towel.
> Regs are Atomic B2.
> Overhauled by factory every 2 years.
> Last overhaul, told by tech there was "no trace" of water in 1st stage. "Excellent shape" was also passed on.

About the only "wierd thing" I do, is at the end of the day, I wash my reg while still pressurized from a cylinder.

For my experience, DIN is no more sensitive to incidental, non pressurized water intrusion than Yoke.

All the best, James

 

[pescador775]

When filling a tank with yoke valve, I crack the valve and let some air blow against my palm. The back blast clears the valve orifice easily and makes one confident that the tank is getting a dry fill. The only water problem with a yoke regulator is due to the dust cap. This cap must be dried off before clamping to the reg. The DIN setup, which includes a deep, water contaminated socket, is a bit more problematical and great care must be taken to dry the valve before filling the tank. If the pump jockey has dried the valve, and the regulator has been wiped by the owner, then there should be no problems with the tank or regulator. When filling tanks, I do not assume that the owner has paid attention to water. Moreover, the environment on a boat is such that wet hands and spray are the norm; decks are wet, practically everything is wet. All this means is that care must be taken and close attention must be exercised with DIN connections.

 

[gcg]

the corrosion on the brass filter will not block the orriface however your friend should be concerned that, where there is oxidation there are particles getting into his air supply and possibly into his lungs. so while he could continue to dive the reg it would be much better to have the reg serviced. i personally dont mess with my OW/salt regs untill i exsperiance performance issues or the little filter starts to show mineral buildup or corrosion. but then i thuroughly clean and test my regs at the shop frequently so i know my gear very well, and i service mine as well as others.