Helium valve
The helium valve is a safety feature found in diving watches that protects the watch from damage caused by the prevailing pressure at certain water depths. It allows helium molecules to escape during saturation diving and the decompression phase, thus ensuring that the watch's sapphire crystal is not pushed out.
But how does the helium valve work? In professional deep diving, divers are in pressurised chambers and breathe in a gas mixture of helium and oxygen (heliox). The helium replaces the nitrogen contained in normal air, which has a narcotic effect in overpressure. The helium molecules are so small that they can penetrate through the seals of a diver's watch into the case. During decompression, however, they cannot escape quickly enough so that, as mentioned above, the glass of the watch can pop out. The helium valve ensures that the helium molecules escape quickly, thus preventing damage to the watch. These valves are superfluous for recreational diving, i.e. at much shallower depths.
Watches with helium valves first appeared in the 1960s. As so often in the history of watchmaking, a prevailing problem and the initiative of an ingenious watch manufacturer led to the creation of a watch icon. At the time, divers complained about watch crystals falling out during decompression. Rolex then developed the helium valve together with the French diving company Comex. Initially, it was retrofitted submarine models that had the helium valve. The Sea-Dweller was finally launched in 1967. Alongside the missing date magnifier and the improved water resistance of 610 metres, the valve is one of the most important features of the Rolex Sea-Dweller. The first model of this watch, which was developed for diving professionals, had the reference number 1665 and was nicknamed "Double Red" because the words "Sea Dweller Submariner" appeared in red on the dial.
The best-known of the watches with a helium valve is the Rolex Sea-Dweller reference 126600, which was launched in 2017 to mark the 50th anniversary of the model series. Compared to its predecessors, it has "grown" by 3 mm to 43 mm and is still sealed up to a water pressure of 120 bar. For the first time, the well-known cyclops magnifier has been installed in this watch to make the date easier to read. Thanks to the new 3235 movement, the watch has a power reserve of around 70 hours. Also worth mentioning is the Omega Seamaster Planet Ocean 600 m (e.g. reference 215.30.46.51.99.001 or 215.30.44.21.01.001). Omega offers various functions with this model series. From the three-hand watch, the GMT watch to the chronograph, you will find what you are looking for with the Planet Ocean. However, unlike Rolex, Omega's helium valve has to be operated manually. Furthermore, the Seamaster Planet Ocean from Omega is anti-magnetic up to 15,000 gauss. Finally, the Tudor Pelagos is a representative of the helium valve watches. Its case is made of titanium and is therefore lighter, but just as hard and corrosion-resistant as stainless steel. Its speciality is the safety folding clasp. It has a patented strap extension that automatically contracts as the pressure increases and thus becomes tighter. When the pressure decreases, the strap lengthens again.
