The History and Reasoning Behind Helium Escape Valves

par {{ author }} JUNJIE ZHANG au Feb 22, 2024

The History and Reasoning Behind Helium Escape Valves
The History and Reasoning Behind Helium Escape Valves:
The development of the helium escape valve can be traced back to the 1960s when professional saturation divers began using diving bells and pressurized habitats for extended periods underwater. These divers would spend days or weeks in these environments, breathing a mixture of helium and oxygen known as heliox.

During prolonged stays in high-pressure environments, helium molecules would penetrate into the watch case, particularly through its gaskets and seals. As the divers resurfaced, the reduction in pressure would cause the helium trapped inside the watch to expand rapidly. This could potentially lead to damage to the watch, such as popping off the crystal or compromising the seals.

To address this issue, watch manufacturers, most notably Rolex and Doxa, developed the helium escape valve. The purpose of an HEV is to allow the built-up helium to safely escape from the watch during decompression, preventing pressure-related damage.

How a Helium Escape Valve Works:
The helium escape valve is a one-way valve that is typically located on the side of a dive watch case. It consists of a spring-loaded valve that opens when the pressure difference between the inside and outside of the watch reaches a certain point.

During saturation diving, when the helium gas inside the watch expands due to the reduction in pressure during decompression, the excess gas exerts pressure on the valve. Once the pressure differential reaches a specific threshold, the valve opens, allowing the helium to escape from the watch without causing any damage.

It's important to note that the helium escape valve is not necessary for recreational divers who do not engage in saturation diving. For most recreational diving scenarios, the pressure differentials experienced are not significant enough to warrant the use of an HEV.

In summary, the helium escape valve was developed to protect dive watches used in professional saturation diving. By allowing excess helium to safely escape from the watch during decompression, the valve helps prevent pressure-related damage and ensures the watch's integrity.