Jump to content
  • Current Donation Goals

Why Have A Helium Escape Valve?


Recommended Posts

Just to start tho - divers do not dive for several days - divers live in saturation diving chambers for up to 28 days and transfer to the bell in teams for the duration of the dive only before transferring back to the chambers...and as far as the physics goes - yes I am qualified and experienced with Archimedes, Boyles, Charles', Dalton's, Henry's etc etc - by the way, the term saturation refers to the fact that a divers body is saturated with a helium and oxygen mix of gases under pressure...and so is his watch (and everything else in the chamber)

No offence intended, and thanks for the reply--didn't mean to disturb you at work. But I don't quite see how what you're saying (specifically above) differs much from the "experts" description.

Looking forward to the rest of the story.

Link to post
Share on other sites
  • Replies 58
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

Hey DiverDoug! I'm glad you resurrected this thread, what a great read with all the old timers.

Thusly, an HEV on a rep is only for decoration and serves no functional purpose, as no rep watch could ever dream of going that low. So, long story short, no need to ever open your watches HEV; make sure the gasket inside is silicone greased and your HEV is securely screwed down before each swim. And don't swim in a watch, unless you've paid the $15 to have it pressure tested. :)

Ciao.

thank you gioarmani for very interesting reading. I have always wonder about it and now you answered it for me.

By the way, where did you go to get your watch(es) pressure tested for $15?

Link to post
Share on other sites

Puggy is correct. Even though the term "molecule" usually consists of at least 2 atoms, He is an inert gas and in its natural state, with all its valence shells filled its atoms do not form compounds, so usually an atom of He is just referred to as a molecule of He as well and vice versa.

Eddy

Link to post
Share on other sites
thank you gioarmani for very interesting reading. I have always wonder about it and now you answered it for me.

By the way, where did you go to get your watch(es) pressure tested for $15?

Call around to your little, hole in the wall watch-repair places. See what they have (i.e., Bergoeon, AF Swiss, etc.), how deep they test to, and how much they charge. ADs are ass rape when it comes to petty thing like that, so avoid them. I was nice enough to make an acquaintance at my AD who was kind enough to test my SMP & Subs for free (I'm sure it had nothing to do with the $$$ I dropped there over the years...)

Link to post
Share on other sites

interestingly enough when tokunaga-san designed the 300m and 600 and 1000m meter seiko 'tuna can' professional divers he patented an 'l-shaped gasket' that prevents he from entering the case and eliminates the need for the valve all together ;)

of course seiko is also the watch company that has for decades produced the scuba master line of professional dive computers for real divers too!

http://www.tokunaga.ne.jp/en/museum/list.html

Link to post
Share on other sites
You're always looking for graduates. I hereby name you Mrs Robinson. :D

Helium is monatomic, yes. It is almost always on its own. This doesn't stop it from being a molecule that comprises of a single atom.

Ok Captain (:D) but in your previous posts you appeared to use the word molecules in its plural sense only (i.e. "split the He atoms from the molecules"), which I thought was strange given that it was Helium we're talking about. If you meant the word in its singular sense, then I think we're saying the same thing :)

Link to post
Share on other sites

We're going diving again so I'll have to be quick.

@gioarmani - no offence taken friend.

@nanuq - the deepest 'dry' dive in diving history (chamber simulated) was around 1,800 feet - no commercial dive (diver) has ever gone to this depth - do you mean 180 feet? If not, please PM me with details.

@z80 - the best reason for having an He valve is that they work and avert an inherent danger in all watches exposed to He in pressurised saturation over lengthy periods (accurately explained by nanuq - watch crystals can and do 'pop off' at very high speed - possibly with over 10+ tons of back pressure helping them on their way).

I've printed off all the topic responses and will do my best to post a reply ASAP - hopefully tomorrow depending on workload.

Apologies for the short post

themuck

Link to post
Share on other sites

go here

www.thedoxabook.com

click on the excerpts link and open the Flash Paper file called Conquistador. It is an excerpt from a book on Doxa Dive Watches (300 pages and 330 images) and should be published very soon. It was hoped to have it out by Christmas, but Doxa are a bit slow with the final edit.

You should find the Conquistador section interesting.

Cheepo

Edited by cheepoguy
Link to post
Share on other sites

Flagged this thread for a good read indeed. Thanks to both Gentlemen who are "educating" us, and I look forward to the outcome, no winners, no losers, just all of us more informed!

Esmarc :pimp:

Link to post
Share on other sites
Ok Captain (:D) but in your previous posts you appeared to use the word molecules in its plural sense only (i.e. "split the He atoms from the molecules"), which I thought was strange given that it was Helium we're talking about. If you meant the word in its singular sense, then I think we're saying the same thing :)

If you think you're only going to encounter only one He molecule, then you don't need an HEV. :Jumpy:

Link to post
Share on other sites
Flagged this thread for a good read indeed. Thanks to both Gentlemen who are "educating" us, and I look forward to the outcome, no winners, no losers, just all of us more informed!

Esmarc :pimp:

Right on E!

The very reason we leave these sorts of threads open, before putting into the KBase.

As a (former) diver, who has used heliox, but never been involved in saturation diving, I find this a most informative thread, and look forward to its conclusion/s.

Thank you gentlemen, please continue to enlighten us.

Offshore

Link to post
Share on other sites
If you think you're only going to encounter only one He molecule, then you don't need an HEV. :Jumpy:

No, the question is whether the encounter is with lots of individual He atoms... or whether it will be with lots of He molecules in the sense you used (i.e. chemically combined He atoms). :D

Link to post
Share on other sites
  • 6 years later...

Wow! I wish this thread would have continued, as I would've loved to hear themuck's explanation. As a former commercial diver and dive instructor myself who has spent more than a few hours in a chamber (never using Heliox though or in sat), I can safely say that a helium release valve is pretty much a gimmick. As it stands now, there are probably less than 2000 (high estimate) of sat divers working now (unless you have $25K for a course, not including the costs of training just to be eligible for sat training). The helium release valve actually has nothing to do with depth of water, but more from being in a hyperbaric environment (although the same pressure, a hyperbaric environment is totally dry) that has helium in it. When you are decompressing in a hyperbaric environment, because of the difference in sizes of He atoms (as opposed to N atoms in air), there are different rates of escape from spaces in the watch. I've worked with sat divers who have had their company-purchased rolexes either explode or implode while in the chamber, so it does happen. However, given that 99.99% of people who have a He-release valve will never have the need for one, I look at it as a gimmick. Exactly the same way that it is irrelevant having a watch that is waterproof to more than 100 m, as you'd probably have a dive computer and backup. Seriously, most divers will never dive below 50m anyway because it takes some pretty advanced planning and specialised diving gear (including mixed gas)

 

 

Also, given that the time of a sat dive is controlled from outside of the saturation complex, there is actually no real reason for saturation divers to even have a watch because their time spent underwater is irrelevant. Because their bodies are saturated, their decompresssion times will remain the same (assuming they are always at the same depth for the duration of the dive), and this is controlled by the panel operators so there is no real need for a diver to bother looking at a watch (since they can't leave the chamber anyway).

 

Still, this is not going to stop me from getting a PO ! :-)

 

Just my two cents on this topic in case anyone was interested....

 

 

Diver Doug

Link to post
Share on other sites

"Also, given that the time of a sat dive is controlled from outside of the saturation complex, there is actually no real reason for saturation divers to even have a watch because their time spent underwater is irrelevant. Because their bodies are saturated, their decompresssion times will remain the same (assuming they are always at the same depth for the duration of the dive), and this is controlled by the panel operators so there is no real need for a diver to bother looking at a watch (since they can't leave the chamber anyway)."

Very true and anyway if you want to know the time you can always ask the topside via comms, wether in the water, bell or chamber.

A sat diver once told me that his submariner (no He valve) exploded while decompressing, said he gathered up the bits and posted them to Rolex who refurbished it for him free of charge. That was in the early days of the North Sea.

Link to post
Share on other sites

Thanks for your input, Stag. Are you an ex-C-DUC as well? I worked on a dive job once (in a place in Australia called Weipa, which I'm sure is Aboriginal for "Fakking big ass crocodiles"!) where there were North Sea sat divers as well. One said that his Rolex actually imploded while being pressurized. The good thing was they were watches issued to the divers by the company, Comex. I would imagine the early days of sat diving in the North Sea during the 70s would've been pretty wild!

One good example where the helium valve may be of some use would be for hyperbaric welders, where their habitat (ie the job site) would be 100 % helium.

Still, even though they are a marketing gimmick, they look pretty cool ! :-)

Link to post
Share on other sites

I saw on another forum where an actual offshore diver tested a Rolex rep (a sub or SD) by actually attaching a rep to the side of the dive bell. I think it was good to a little over 100m. I'll try to find the link somewhere. It was a great read with photos too!

Link to post
Share on other sites

I worked on a dive job once (in a place in Australia called Weipa, which I'm sure is Aboriginal for "Fakking big ass crocodiles"!) where there were North Sea sat divers as well. One said that his Rolex actually imploded while being pressurized. The good thing was they were watches issued to the divers by the company, Comex. I would imagine the early days of sat diving in the North Sea during the 70s would've been pretty wild!

 

Hey Doug, it's nice to have you aboard.  And thanks for bringing this topic back to life! 

 

My buddy was one of those 70s divers that worked the North Sea.  He told stories of the deepwater manifolds where the flow lines from the oil production facilities connected, and having to work down there.  He was all over the world doing sat work, and was involved in getting Man in the Sea running.

 

Unfortunately he tore his foot off and ended his diving career, then passed away two years later.  At his funeral his widow gave me his dive watch, bearing the scars of many years hard work.  He told me once that he'd had it to its rated depth in chambers, but who knows how much of that was arm-pulling?  He also talked about coworkers laying around for days on end decompressing with him, then someone's crystal would blow off and they'd all jump out of their skin.  This was back when I had no idea there was such a thing as a "Sea Dweller".

 

 

dr_wabi.jpg

Link to post
Share on other sites

×
×
  • Create New...