Scuba Tank Valve
Scuba Tank Valve make up an integral part of every diver’s underwater breathing equipment as it opens and closes the tank. It’s also the part that connects to your regulator, so it’s crucial for every diver to be familiar with both.
While there are several styles of scuba valves available, they essentially have the following components:
The knob is what opens and closes the valves, allowing you to control air flow. Turning the knob left (counterclockwise) would open the valve while turning it right (clockwise) would close it.
Scuba valves typically have an O-ring that helps create a secure seal between the valve and the regulator. However, it can sometimes be on the regulator itself, depending on the connection or attachment method used (more on this below).
This thin copper disk is more of a safety feature that is designed to rupture once the tank’s internal pressure reaches a certain level, thus helping divers avoid serious bodily injuries.
Yoke Tank Valve
Also referred to as the A-clamp or international fitting, the yoke was the standard connection for many tanks around the world. A yoke regulator connection features an oval metal brace that fits over the top of the tank valve. It also has a rotating black plastic handle that’s used to tighten the regulator’s metal yoke screw onto the tank valve.
The O-ring, which is situated visibly on the yoke valve itself rather than on the regulator, expands by air pressure as it tries to create a seal between the valve and regulator. As a result, the yoke valve O-ring will eventually wear out or get damaged, causing air leaks that can cause minor to major disruptions of air supply if it is not replaced.
Nonetheless, the yoke fitting is most commonly used around the world and is still the ideal (and most affordable) connection for tanks with average pressure ratings.
DIN Tank Valve
DIN (short for the Deutsches Institut Für Normung) is a German-standard setting that is rapidly increasing in popularity. It is more widely used outside the US and is indispensable for technical and deep divers for its ability to withstand higher maximum pressures of air (over 3000 psi).
What makes a DIN fitting different is that its “captured O-ring” seal is thicker, more dependable, and is attached to the regulator connector instead of the tank valve. At the same time, the regulator connector doesn’t have an oval metal brace (so it is less bulky and doesn’t have to be clamped on) and can be screwed directly into the DIN compatible valve.