Helium Escape Valves and my findings

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Helium Escape Valves and my findings

Post by koimaster » October 28th 2019, 3:55pm

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I know a lot of dive watch fans see a helium escape valve as a potential failure point, a gimmick and pretty much useless unless your a saturation diver but I thought I would give you an insight as to how it works and how it is needed for Saturation Divers.

Life under pressure takes many forms, first the initial blow down to your living storage depth, this entails the Heliox gas mix to be put into the dive system, a living depth of 100m may take a couple of hours to reach, then the living depth is maintained to make sure it stays at 100m.
Part of the way into your dive trip the pressure may be increased or decreased depending on the water depth, it takes much longer to decrease depth (decompression) it's about 1 metre an hour, this may happen a couple of times during your trip and trips are no longer than 28 days.

The life of a watch in a saturation dive system for this trip is complex and I have experienced many situations with lots of different watches but for the past five years I've made a note of different things happening to my own Scurfa Watches. The early models would go into the dive system no problem as long as the crown was unscrewed and pulled right out, occasionally the crown would be pushed back in and that would be enough to seal the watch and the glass would pop out, this has happened a few times and there is no rhyme or reason to when it would happen. I improved the models and found I could no longer take my watches into the dive system, sometimes the glass popped and sometimes it did not.

The Bell Diver 1 with the Heliox Escape Valve was extensively tested and took 15 months to get right, I tested the case first then the finished watch and that worked no problem.
On the initial blow down most of us open our watches to allow the pressure inside if we do not do this the pressure on the crown will not allow us to unscrew it, this means we will not be able to change the time or date if we sail to a different time zone and it takes about five days for the gas to penetrate the watch, companies have tried to make watches impregnable to helium but they have never actually lived in a saturation dive system for a month and also on a ship, a watch un-equalised is pretty much useless.

A problem I have now found with allowing the pressure inside is other foreign bodies get pushed inside also, the dirt that can build up around the crown over time can be forced inside, this I have discovered is not a new problem, some of the older divers who wore the Comex submariners and sea dwellers used to get a movement service every winter when the work stopped, I could never understand why they did this until now. Me and a lot of my colleagues who wear the bell diver have had this happen and it was my watchmaker who explained it, he's a Rolex trained watchmaker and over the winter months would service a few regular divers watches.

The helium escape valves themselves can also be a problem, the manual ones are pretty much useless as they can be pushed back in and take a seal, they can also fail when unscrewed as the rubber gaskets can be pushed outwards into the crown/cover and also take a seal.
The automatic valves work really well but can trap pieces of fluff from your clothes when they are activated, this can have an affect on the water resistance.

A couple of freak incidents that have happened over the years to other watches include, the dial being forced around 180 degrees on initial blowdown, watches packed tight in bell bags preventing valves from operating, back gaskets popping out during decompression, gaskets pushed inside during blowdown, a loose crown that had pressure on during blowdown felt tight before a dive, equalised during the dive and allowed water in, a watch dropped onto the helium escape valve allowing moisture in during a shower and a few explosions caused by false HEV's.

I hope you found this thread informative and I'm not naming any names but if some of the large manufacturers knew the implications of taking a dive watch into a saturation dive system I think they would think twice before fitting them

https://forums.watchuseek.com/f74/heliu ... 46395.html

I do not like the misleading comments about "commercial Divers" made by some watch companies. Carl could chime in to this for a better understanding. My reading has shown the following-

1. Recreational diver on air, that limit is 130 feet.
2. Helmet air supplied commercial diver, 200 feet.
3. Mixed gas helmet diver, 300 feet
4.Bell-bounce diver going to 600 feet for short durations.
4.Mixed gas Saturation diver, 2,000 feet.


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Re: Helium Escape Valves and my findings

Post by bedlam » October 28th 2019, 5:08pm

Scurfa explains that the HRV on a dive watch is useful to saturation divers...as if anyone disagreed with that. Outside of that very highly specialised context it is totally a marketing gimmick.

It's not clear to me that saturation divers need dive watches at all - they have computers like I do and a team of support people monitoring all their issues during the dive. A bunch may as well be wearing a field watch with an HRV fitted for use in the bell because I doubt many wear their watches in the water in the saturation diving context.

I don't have any personal experience in helmet, hookah or saturation diving, but general scuba related limits are as follows.

Advanced open-water dive accreditation - 30m (100ft)
Recreational dive limits - 40m (130ft)
Limit for using standard air - 55m (180ft)
Limit for technical diving accreditation - 100m (330ft)
Record for scuba diving - 332m (1090ft)
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