Regulator and Tank Valve Terminology

[OMyMyOHellYes]

There's also a 3rd DIN standard commonly called M26 or M26x2 (@OMyMyOHellYes will explain why that's wrong and give us the correct name) which is only used in parts of Europe and is not compatible with anything else. It was introduced in a misguided attempt to separate air and dedicated Nitrox equipment.

Nah. It's a silly Euro thing. It has no relevance so does not warrant discussion. Actually, from what I have read, it has no relevance to anybody in Europe. Except the French.

But, a K valve would never be found with that connector.

 

[Wallowa]

A K valve is a type of valve used on scuba tanks to control the flow of air from the tank to the regulator. It's one of the most common types of valves, especially in the United States1. Here are some key features:

• Simple Design: The K valve has a straightforward on/off mechanism controlled by a single knob.
• Yoke Attachment: It uses a yoke (or A-clamp) attachment to connect the regulator to the tank. The regulator is slipped over the valve and secured with a screw1.
• O-Ring: An O-ring creates a seal between the valve and the regulator, which can wear out over time and should be inspected regularly.
• Burst Disk: A safety feature that ruptures if the tank's internal pressure gets too high, preventing potential injuries.

The J valve is another type of valve used on SCUBA tanks, and it's particularly interesting due to its built-in reserve mechanism. Here are some key points about the J valve:

• Built-in Reserve: The most notable feature of the J valve is its built-in reserve air supply. When the tank's pressure drops to a predetermined level (typically around 300-500 psi), the valve restricts the airflow, signaling the diver to switch to reserve mode and providing additional air to safely ascend.
• Manual Lever: The valve has a manual lever that the diver can pull to access the reserve air. This lever is often called a "reserve handle" or "J rod."
• Yoke Attachment: Similar to the K valve, the J valve uses a yoke attachment to connect the regulator to the tank.
• O-Ring: Like other valves, it has an O-ring to create a seal between the valve and the regulator.

The J valve was more commonly used before the advent of modern submersible pressure gauges (SPGs), which allow divers to monitor their tank pressure throughout the dive. With SPGs now standard, the use of J valves has declined.

A Beginner's Guide to Scuba Tank Valves - Scuba.com

If you’re a beginner scuba diver, check out this quick guide to scuba tank valves to understand scuba tank and regulator compatibility.

www.scuba.com

 

[Cthippo]

No, you're all wrong!

The K valve is on the inflator and controls air into (and out of) the BCD!