As a scuba diver, you’re probably quite comfortable with the yoke valve. It’s been standard almost since scuba was invented. Increasingly, however, manufacturers are producing tank valves and regulators with the newer DIN valve. Scuba-diving forum debates brim on the web with discussions as to which one you should use. Let’s try to clear up the pros and cons when it comes to DIN versus yoke valves.
First, what is the difference between them? The yoke is a clamp-type mounting, which is placed over the tank valve and then tightened into place. The DIN is a threaded valve, wherein you screw the regulator into the tank valve. On the yoke valve, the main O-ring that seals the tank valve to the regulator first stage is placed on the tank valve. On the DIN, it is placed on the regulator first stage.
The name “DIN” is an acronym for Deutsche Industrie Norm, an industrial testing and approval agency based in Berlin, Germany. The agency standardizes a range of products, about 30,000 at present, within the fields of mechanics, engineering and technology. However, the DIN valve was actually invented in the U.S. In the late 1950s, American diving manufacturer Poseidon launched what they named their “⅝-inch Threaded Connection.” But it didn’t enjoy much public support and the yoke valve became the standard for scuba diving. When DIN tested valves on pressure tanks for industry use, including commercial diving, they made the ⅝-threaded their standard, and it thus inherited the name of the organization.
The German agency chose DIN for its higher pressure capacity, which comes in handy for industrial use and commercial diving. Whereas a yoke valve is generally only approved to a maximum working capacity of 200 bars, a DIN valve can be set up to handle up to 300 bars.
The first recreational divers to use the DIN were technical divers, not only because the extra capacity of 300 bars may come in handy, but also because of the increased safety that the DIN claims. The safety issue has long been a point of discussion among divers; some claim that anything but DIN is downright lethal, while others claim that the DIN isn’t really safer than a yoke at all.
Theoretically, the DIN does have safety advantages. The greater pressure capacity can reduce the risk of a rupture in case of overfilling when the tanks are attached to a compressor. Sine the O-ring in a DIN is in the regulator, rather than on the exterior of the valve as in the yoke, it’s less likely to be lost or damaged during transport. Tests have also shown the DIN to be more resilient to impact compared to a yoke, which can be knocked off — an unlikely, but not impossible, scenario.
However, don’t jump to any conclusions about the yoke valve. Millions of dives have been conducted with yoke valves since scuba diving became popular, and it’s been proven to be plenty safe. It’s similar to debating whether the new Airbus 380 is safer than the old Boeing 737. On paper, the 380 has more safety features, but the 737 has millions of air miles to its name, with minimal accidents. It is also worth noting that DAN and other dive-safety organizations do not have policies against yoke valves. Technical diving, as a different discipline, may call for different tools. Tec divers do sometimes use higher working pressures in their tanks, up to 300 bars. When diving inside wrecks and caves, the increased protection against catastrophic impact damage, however marginal that risk, is worthwhile.
The tanks you rent on vacation typically feature yoke valves, so most traveling divers choose a yoke to ensure compatibility. If you prefer DIN, but still want to rent tanks, it’s usually a matter of removing a small insert from the yoke valve so that it will accept the DIN reg. If this doesn’t work, there are also DIN/yoke converters that will fix the problem.
A personal choice
Price-wise, the playing field has leveled in recent years, too. In the past, DIN was only available for high-end or tech-specific dive gear. Today, many entry-level regulators offer either a yoke or DIN, depending on the customer’s preference.
So, if you’re primarily a tec diver, you’ll probably want to go with DIN. If you’re not a tech diver, it’s a personal choice. The cost is about the same, and you can easily remedy the problems of traveling and renting gear. Considering the DIN’s advantages, however small, even for recreational divers, I dive with a DIN. But again, it’s a purely personal dive choice.