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Sinn 103 ST Diapal
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Discussion Starter · #1 ·
Hi everyone !
I've noticed many of you mentioning the expression "HRV" I've tried to google the phrase but can't manage to find out what it's a short for. Could any of you please tell me what it stands for ?

Thank you

Best regards
Mr Milshark
 

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From Wikipedia...
"A helium release valve, or helium escape valve, as it is also called, is a feature found on some diving watches. It provides functionality for professional divers operating at great depths for prolonged periods of time.
When commercial divers operate at great depths, they often spend prolonged hours in diving bells under pressure breathing a gas mix like hypoxic trimix or similar, that contain the gas helium. Since helium molecules are the second smallest found in nature, the gas is able to work its way inside the watch, around any o-rings or other seals the watch may feature. This isn't a problem as long as the divers stay under pressure, but when they resurface, the helium inside the watch starts to expand quicker than it can escape, leading to an increase in pressure inside the watch. This can cause great damage to the watch, even making the crystal pop off.
To prevent this, Rolex and Doxa invented the helium escape valve in the 1960's. This is a small, one-way valve, usually featuring a screw-down crown on the side of the watch. When the diver starts to ascend he or she simply unscrews the crown to the full open position, allowing any helium that may have been trapped inside the watch housing to escape. Usually used in a dry environment (inside a diving bell or in a saturation chamber), the fact that the valve is one-way also means that it can opened while the watch (and diver) is submerged."
 

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Discussion Starter · #4 ·
many thanks for the great info on this. As i reads your thread i realised that two of my watches features this HRV then ; the Certina DS-3 and SMP :) Thanks once again
 

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From Wikipedia...
"A helium release valve, or helium escape valve, as it is also called, is a feature found on some diving watches. It provides functionality for professional divers operating at great depths for prolonged periods of time.
When commercial divers operate at great depths, they often spend prolonged hours in diving bells under pressure breathing a gas mix like hypoxic trimix or similar, that contain the gas helium. Since helium molecules are the second smallest found in nature, the gas is able to work its way inside the watch, around any o-rings or other seals the watch may feature. This isn't a problem as long as the divers stay under pressure, but when they resurface, the helium inside the watch starts to expand quicker than it can escape, leading to an increase in pressure inside the watch. This can cause great damage to the watch, even making the crystal pop off.
To prevent this, Rolex and Doxa invented the helium escape valve in the 1960's. This is a small, one-way valve, usually featuring a screw-down crown on the side of the watch. When the diver starts to ascend he or she simply unscrews the crown to the full open position, allowing any helium that may have been trapped inside the watch housing to escape. Usually used in a dry environment (inside a diving bell or in a saturation chamber), the fact that the valve is one-way also means that it can opened while the watch (and diver) is submerged."
Well, I leaned something new! I'd been under the impression that Helium WAS the smallest, not second smallest atom. Now I need to google the smallest to discover what it is :-d. Thanks for the informative post, this was the most complete and concise definition of the HRV I've seen yet. Well done :-!.

BTW, to clarify for those imagining a Doxa with that thing sticking out to be un-screwed, many HRV's do not feature a screw down crown. The Rolex Sea Dweller, the Doxa Conquistador, the Breitling Superocean and the Certina DS-3 (my only HRV equipped watch.... to date ;-)) all feature a valve that is simply flush with the case. I can't imagine Doxa going the screw down crown route for an upcoming HRV project.
 
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