Tank Valve Etiquette


Don’t be a valve violator

by Jesse Iacono

As with many outdated habits in the scuba industry, there are a couple surrounding tank valves that simply refuse to die. This article serves to identify the two most heinous and commonly occurring of the valve violations. Changing these habits now could save your reputation and even your life.

Take heed of the following advice to avoid becoming branded as a valve violator!

1. The Cap Blaster

Our first valve violator is certainly one who commands the attention of everyone at the dive site. This individual can be found using blasts of gas from their tank to clear excess water off of their dust cap. Although the results of this violation don’t present much of a direct threat to safety, their effects on surrounding divers are often unconsidered.

This method of drying dust caps is no more effective than blowing on them and/or using a towel to accomplish the same task. This method is, however, exponentially louder and completely unnecessary. The sound created can be startling and harmful to the ears of anyone in close proximity as well as a major distraction to the nearby dive professionals, boat crew, and captain. Remember, these are the individuals whose focus on their task has an impact on the safety of those around them. As a dive professional, the sudden sound of gas exiting a tank is interpreted as a red flag that something is wrong and needs to be dealt with immediately. By creating this false alarm, one can expect the focus of the surrounding dive professionals to immediately be drawn to them as a second-nature response. Also, when using a yoke valve, as the gas from the tank is reflected off of the cap and directed back towards the valve face, it can easily dislodge the o-ring, rendering the tank useless until the o-ring is found and replaced or a new one is purchased. The costs associated, although not very significant, can add up over time and are easily avoided.

This habit seems to rampantly spread between divers, sometimes even those who were trained to do the opposite.  Eliminating this one from your repertoire can spread awareness and contribute to the violation’s overall demise.

2. The Quarter Turner

Our second violator is one who finds discomfort in certainty. This individual can be found opening their valve all the way and bringing it back a quarter turn. Such adherence to an antiquated practice could prove to be dangerous and even fatal.

This violation stems from a time when valves could get stuck in the open position if turned all the way open and not backed off by a quarter turn. One can move confidently forward knowing that this situation will not occur when using any of the valves manufactured within the past five decades. For some reason, even though the problem has long been solved, the habit sticks and is still transmitted from some instructors to their students.

When it comes to tank valves, there are only two options – the valve is open or the valve is closed, nothing in between.  When a valve is 100% open, the individual can breathe from their regulator while looking at their SPG and see no movement from the needle that indicates the contained pressure. When a valve is 100% closed, the individual can breathe from their regulator while looking at their SPG and see that it either reads zero or, if previously pressurized, the needle will move towards zero with each breath. During one’s final check, performed immediately before entering the water, this offers no confusion as to whether one will have gas to breathe once in the water.

The danger in the quarter turn violation is due to misinterpretation and inability to distinguish a valve that is a quarter turn opened vs. a quarter turn closed. A valve that is turned on 100% and then a quarter turn off and a valve that is turned off 100% and then a quarter turn on will provide the same results when breathing from one’s regulator and monitoring the SPG at the surface – it will seem as though the valve is sufficiently opened and ready for the impending dive. If one were to enter the water with a valve only a quarter turn open, they would quickly encounter a situation involving a lack of sufficient breathing gas, the results of which would prove to be both undesirable and dangerous.

Although making sure one’s valve is open seems simple enough, a single task can easily be overlooked when combined with the many that are required in preparation for a dive.  Add to this the commotion and excitement typically present at a dive site or on a dive boat and it can be easy to make mistakes. Sometimes it isn’t even oneself that is the violator, but a well-meaning individual attempting to lend a hand. By adhering to the correct valve procedures and making sure to always perform a final check before entering the water, one can begin their dive without question.

In every area of diving, make sure to think smart and safe. Trust the information that dive professionals are presenting, but don’t ever be afraid to ask questions about why certain processes are observed. If something seems counterintuitive, sometimes it just may be…

To find out more about International Training, visit www.tdisdi.com.


International Training

International Training

From its humble beginning in 1994 to today, the group of training agencies Scuba Diving International (SDI), Technical Diving International (TDI), and Emergency Response Diving International (ERDI) form one of the largest diving certification agencies in the World – International Training. With 24 Regional Offices servicing more than 100 countries, the company today far exceeds the original vision the founders had when they conceived the idea on a napkin, sitting at a kitchen table in the early 1990’s.

3 Replies to “Tank Valve Etiquette”

  1. John Topham says:

    Totally agree with the comments on the cap blaster, and have seen divers take it further and dry their first stage this way which only results in moisture or grit being blown into the regulator potentially causing corrosion or worse.
    Don’t quite agree with the valve position though. I work with valves, high pressure gasses and liquids every working day and it’s pretty much an industry standard the when a valve is opened it is backed off slightly from the fully open position. Not a significant amount, just to take the tension off.
    I think part of the problem as you mention is well-meaning assistance, however if I see ANYONE touching my gear after I have checked it and set it up for the dive I will start my pre-dive check from the beginning again. Boat crews and guides are used to us Tech divers being touchy about our kit being touched, the same should apply during recreational dives. It does for me anyway. I am the one responsible for my safety.

  2. DQ_AJT says:

    I agree with John. If a valve is free-flowing underwater, the last thing you want is a struggle to get the knob turning because it was left fully open.

    1. John Topham says:

      The trouble is that recreational students are not taught valve drills – perhaps they should be?

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