Helium release valve
Encyclopedia
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 or under saturation
.
When commercial divers operate at great depths, they often spend prolonged hours in diving bells
under pressure
breathing a breathing gas
mix like trimix or similar, that contain the gases helium
or hydrogen
. Since helium atoms are the smallest natural gas particles
found in nature, these gas atoms are able to work their way inside the watch, around any o-rings or other seals the watch
may feature. This is not a problem as long as the divers stay under pressure, but when the decompression stops during resurfacing aren't long enough, a pressure difference builds up between the trapped gas(es) inside the watch case and its environment. Depending on the construction of the watch case and crystal, this effect can cause damage to the watch, like making the crystal pop off.
While many watch companies react to this effect by simply offering an even more robust case/crystal construction, Rolex
and Doxa S.A.
however thought of a different concept when they co-created the helium escape valve in the 1960s (first introduced in the Rolex Submariner/Sea-Dweller and the Doxa Conquistador): A small, spring-loaded one-way valve
integrated in the watch case that is activated when the differential between the inner and the outside pressure reaches a critical level. Result: The valve releases the helium, hydrogen and/or other gases used in the breathing gas mix trapped inside the watch case.
Automatic helium release valves usually don't need any manual operation. There are however helium release valves featuring an additional screw-down crown at the side of the watch. When the diver starts to ascend
, the diver simply unscrews the valve's crown to the full open position, allowing any breathing gas that may have been trapped inside the watch to escape during decompression.
Helium release valves can primarily be found on mechanical diving watches featuring a water/pressure resistance greater than 300 m (1000 ft) and therefore positioned as more extreme dive watches. Models that feature a helium release valve include most of the Omega Seamaster
series, Rolex Sea Dweller
, some dive watches from the Citizen Watch Co., Ltd, Breitling
, Girard-Perregaux
, Panerai
, all watches produced by Enzo Mechana, Aegir Watches and selected Doxa
, selected Victorinox
models, and Oris
models. Other watch manufacturers such as Seiko
still offer high-level dive watches that are guaranteed safe against the effects of helium gas without needing an additional opening in the case in form of a release valve.The most extreme mechanical diving watch equipped with a helium relief valve is the 20'000 FEET by CX Swiss Military Watch, the current world record holder for mechanical diving watches and featured in the Guinness Book of World Records.
Saturation diving
Saturation diving is a diving technique that allows divers to reduce the risk of decompression sickness when they work at great depth for long periods of time....
.
When commercial divers operate at great depths, they often spend prolonged hours in diving bells
Diving bell
A diving bell is a rigid chamber used to transport divers to depth in the ocean. The most common types are the wet bell and the closed bell....
under pressure
Pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
breathing a breathing gas
Breathing gas
Breathing gas is a mixture of gaseous chemical elements and compounds used for respiration.Air is the most common and only natural breathing gas...
mix like trimix or similar, that contain the gases helium
Helium
Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...
or hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
. Since helium atoms are the smallest natural gas particles
Covalent radius
The covalent radius, rcov, is a measure of the size of an atom that forms part of one covalent bond. It is usually measured either in picometres or angstroms , with 1 Å = 100 pm....
found in nature, these gas atoms are able to work their way inside the watch, around any o-rings or other seals the watch
Watch
A watch is a small timepiece, typically worn either on the wrist or attached on a chain and carried in a pocket, with wristwatches being the most common type of watch used today. They evolved in the 17th century from spring powered clocks, which appeared in the 15th century. The first watches were...
may feature. This is not a problem as long as the divers stay under pressure, but when the decompression stops during resurfacing aren't long enough, a pressure difference builds up between the trapped gas(es) inside the watch case and its environment. Depending on the construction of the watch case and crystal, this effect can cause damage to the watch, like making the crystal pop off.
While many watch companies react to this effect by simply offering an even more robust case/crystal construction, Rolex
Rolex
Rolex SA is a Swiss watchmaking manufacturer of high-quality, luxury wristwatches. Rolex watches are popularly regarded as status symbols and BusinessWeek magazine ranks Rolex No.71 on its 2007 annual list of the 100 most valuable global brands...
and Doxa S.A.
Doxa S.A.
Doxa S.A. is a Swiss company, founded in 1889, that manufactures watches. Doxa is best known for its dive watches.-Company history:Doxa, founded in 1889 by George Ducommun, began as a maker of fine dress watches and other timepieces. Over the years, Doxa gained in size and branched out into...
however thought of a different concept when they co-created the helium escape valve in the 1960s (first introduced in the Rolex Submariner/Sea-Dweller and the Doxa Conquistador): A small, spring-loaded one-way valve
Check valve
A check valve, clack valve, non-return valve or one-way valve is a mechanical device, a valve, which normally allows fluid to flow through it in only one direction....
integrated in the watch case that is activated when the differential between the inner and the outside pressure reaches a critical level. Result: The valve releases the helium, hydrogen and/or other gases used in the breathing gas mix trapped inside the watch case.
Automatic helium release valves usually don't need any manual operation. There are however helium release valves featuring an additional screw-down crown at the side of the watch. When the diver starts to ascend
Ascend
Ascend may refer to:* Ascend, an experimental doom metal band.* Ascend , by Greg Howe* ASCEND, mathematical modelling/simulation software* Ascend Communications-See also:* Ascent * Ascension...
, the diver simply unscrews the valve's crown to the full open position, allowing any breathing gas that may have been trapped inside the watch to escape during decompression.
Helium release valves can primarily be found on mechanical diving watches featuring a water/pressure resistance greater than 300 m (1000 ft) and therefore positioned as more extreme dive watches. Models that feature a helium release valve include most of the Omega Seamaster
Omega Seamaster
The Omega Seamaster is an automatic winding chronometer and quartz watch that Omega has produced since 1947. An Omega Seamaster typically has a stainless steel case and bracelet , screw-in crown and caseback, engraved with the Omega hippocampus logo, up to 1200 metre water resistant, phosphorescent...
series, Rolex Sea Dweller
Rolex Sea Dweller
The Rolex Oyster Perpetual Date Sea-Dweller is a line of diver's watches manufactured by Rolex, with an underwater diving depth rating of for the vintage models and up to 3,900 metres for the most recent Sea-Dweller DEEPSEA model.-History:...
, some dive watches from the Citizen Watch Co., Ltd, Breitling
Breitling
Breitling is a luxury brand of Swiss watches produced by Breitling SA, a private company headquartered in Grenchen, Canton of Solothurn . The company exclusively offered Certified Chronometers in all models since 2000...
, Girard-Perregaux
Girard-Perregaux
Girard-Perregaux is a high-end Swiss watch manufacture with its origins dating back to 1791. It is situated in La Chaux-de-Fonds, Switzerland and is a part of the Sowind group, a subsidiary of PPR.- History :...
, Panerai
Panerai
Officine Panerai Marketing e Communicazioni Srl, a wholly owned subsidiary of Compagnie Financière Richemont S.A., designs, manufactures, markets and sells watches under the Officine Panerai brand through authorized dealers and company-owned boutiques worldwide. Giovanni Panerai founded Officine...
, all watches produced by Enzo Mechana, Aegir Watches and selected Doxa
Doxa S.A.
Doxa S.A. is a Swiss company, founded in 1889, that manufactures watches. Doxa is best known for its dive watches.-Company history:Doxa, founded in 1889 by George Ducommun, began as a maker of fine dress watches and other timepieces. Over the years, Doxa gained in size and branched out into...
, selected Victorinox
Victorinox
Victorinox is a knife manufacturer based in the town of Ibach, in the Canton of Schwyz, Switzerland. Since its acquisition of rival Wenger in 2005, it has, once more, become the sole supplier of multi-purpose knives to the Swiss army.-History:...
models, and Oris
Oris
Oris is a manufacturer of Swiss luxury wristwatches. The Oris watch factory was founded by Paul Cattin and Georges Christian at Hölstein in 1904...
models. Other watch manufacturers such as Seiko
Seiko
, more commonly known simply as Seiko , is a Japanese watch company.-History and ongoing developments:The company was founded in 1881, when Kintarō Hattori opened a watch and jewelry shop called in the Ginza area of Tokyo, Japan. Eleven years later, in 1892, he began to produce clocks under the...
still offer high-level dive watches that are guaranteed safe against the effects of helium gas without needing an additional opening in the case in form of a release valve.The most extreme mechanical diving watch equipped with a helium relief valve is the 20'000 FEET by CX Swiss Military Watch, the current world record holder for mechanical diving watches and featured in the Guinness Book of World Records.