If you’re a dive watch enthusiast, you may have already been exposed to a helium escape valve. It’s the round fitting on the side, usually at the 9 or 10 o’clock position, and you’ll find them on many premium dive watches. Typically, helium escape valves are found on professional-grade dive watches, such as the Rolex Sea-Dweller.
What you may not be aware of is what these valves actually do. I’m about to explain what they do, what their purpose is, and why you might want one. Here’s a top-down overview.
What a Helium Escape Valve Does
As it happens, a helium escape valve isn’t necessarily a benefit. Depending on your needs, it might actually be a drawback. Why might this be the case? To understand why this is the case, we need to take a closer look at what a helium escape valve does, how it works, and why you might actually want to use one.
The first thing to understand is that helium is one of the smallest atoms – it’s number 2 on the periodic table, so it’s also exceptionally lightweight. As a result, helium atoms can easily slip through airtight seals that are designed to prevent ingress from heavier atoms like oxygen and nitrogen. This is particularly true in high-pressure environments, where helium atoms can slip through just about any seal.
If you spend a lot of time in a high-pressure environment, helium can build up in your watch to the point where the internal pressure is equal to the external pressure. As long as you remain in a high-pressure environment, this is all well and good. But when you leave that environment and return to the normal atmosphere, the pressure differential can cause the crystal to explode. Needless to say, this won’t just ruin your watch. It can also be hazardous to your health.
A helium escape valve helps you avoid this situation. When the valve is operated, it allows high-pressure helium gas to escape harmlessly from your watch as you transition back to normal air pressure. Because it’s a one-way valve, it also won’t allow ingress, which ensures that water, air, and other larger elements won’t get into your watch while the valve is in operation.
How Does Helium Get In?
By this point, you’re probably wondering how helium would get into your watch in the first place. Who in their right mind would put their watch into a high-pressure helium tank? The answer is that advanced divers might need to spend time in a decompression tank.
A decompression tank is designed to avoid the effects of nitrogen narcosis, which is a buildup of nitrogen in your cells. This condition can cause mental confusion, similar to being under the influence of some illegal drugs. It happens when divers surface to quickly from extreme depths, and is related to “the bends”, a similar nitrogen-related condition.
To avoid nitrogen narcosis, deep sea divers will spend time in a decompression tank on their way up. In order to speed the process of removing nitrogen from your cells, these tanks are generally filled with an air-like gas, which replaces the 70 percent nitrogen from ordinary air with chemically-inert helium. This allows divers to acclimate more quickly, reducing the time it takes to return to the surface. If you’re wearing your dive watch inside a decompression tank, it’s likely to fill up with helium. And if you can’t decompress your watch on the way up, it’s liable to explode.
As you can see, the majority of divers aren’t ever going to use a helium escape valve. Most divers never go deeper than 40 meters, which doesn’t require you to spend time in a decompression tank. As a result, only professional divers or dedicated enthusiasts are ever going to need one of these valves.
So, what’s the downside? Simply put, any extra parts or holes are just another part that can potentially fail. True, a well-engineered watch shouldn’t fail easily. However, if you don’t need one, why would you add an extra point of failure?
Why Are These Valves So Popular?
Given all of this, why on Earth would an ordinary diver or watch enthusiast want a helium escape valve? Essentially, it comes down to marketing. After all, surely the best divers will use the best dive watches. And surely, if those people are using watches with an escape valve, that’s what everyone should own. At least, that’s the public perception.
In reality, for 99 percent of people, this is just a marketing gimmick. Don’t get me wrong. Helium escape valves have their place, and serve a vital function for deep sea divers. But for the vast majority of people, they just add extra expense, as well as introducing an unnecessary point of failure.