troubleshooting problems

[Ben_Ayers]

Greetings,

Was just reading another thread and picked-up another tidbit I didn't know regarding troubleshooting problems. A diver went "OOA" at depth and the post incident evaluation revealed that the air valve was not all the way on. A member pointed out that if the diver would have glanced at his pressure gauge while trying to breath, he would have seen a wildly fluctuating needle-didn't know that!
I also remember reading where someone always takes 2-3 breaths on their reg. while watching the needle (I think looking for movement) before entering the water.
Neither of the aforementioned nuggets of info. were in my OW text (that I recall).
These "tidbits" got me thinking about algorithms for problems or what symptoms to expect with certain problems.
Most appliances have a troubleshooting guide in the manual. The guide may list potential problems with their likely symptoms and finally how to fix the problem. Others may have an algorithm that starts with a situation and gives certain things to check in a certain order.
Is there anything like this online or in a book for common scuba problems? Or do you have/know of any other "insider" nuggets like those above?

Thanks a bunch,
Ben

 

[Doc]

I was the one that threw down those two notes.

If the needle drops from 3000 and bobbles downward only to return back to 3000 after a few quick breaths- the valve is just barely cracked, most likely.

If the needle drops sequentially with each breath, there may have been air in the hoses at 3000psi, but none came out of the tank to replace it as you sucked it down.

Either way, bad bongos.

Remember that key point I added- most digital gauges will not work for you like this.

Unfortunately, when this is happening, there is not much opportunity to flip open to Page 86 where the Trouble Shooting Matrix is located, much less waiting for your 56k connection to load with the digital version.

A flippant way of saying that unless you are intimately aware of systems, unless you have the composure to instantly diagnose and evaluate, maybe it's best to ditch everything and make for the daylight.

Kind of like re-explaining reverse block to someone as they are enjoying it for the first time.

It wouldn't be a bad list to put together, not so much as a reference guide, but more of a read and regurgitate memory test. Could save a life.

 

[hudson]

If you can reach your valve and check that's the best way to do it. If you can't, try resting the bottom of the tank on a nearby flat surface for a moment, that usually does the trick if your tank isn't too low. Personally I go through a mental check head to toe before I jump in. Do I have my mask? Is the hood in place (yes I did jump in 50F water without my hood)? Is the octo secure and comfortable on the necklace? Are the shoulder straps in place/not twisted?..................................ending with: Thigh pocket contents secure? Fin straps secure? This provides a complete equipment check and since I'm visually going by location I never miss anything. Takes about 30 seconds including inflator and regulator checks.

 

[ruready7]

Thanks for the information. I will be watching my needles when I take those first few breaths.

 

[Ben_Ayers]

I was thinking of a learning tool, not something to laminate and attach to my bc LOL. So the needle should not move with 2-3 breaths, if it does something is amiss! I think I need to become intimately aware of systems- hello PADI. Maybe Dive Con?
Reverse block? Bought the tee shirt on that one.In 1986 my instructor explained reverse block to me after I surfaced with blood coming out of my ear.

Thanks,
Ben

 

[Ben_Ayers]

I just remembered another "symptom". Had this happen during pool session the other night. My regulator (Atomic something) sounded like a whoopie cushion during exhalation. It was working okay, but vibrated and "passed-gas" upon exhaling. Anyone know what causes this and is it a problem?

Ben

 

[Prostar]

The information to which you refer is called the Rescue Diver course. I urge everyone to take it. By no means am I trying to sell more classes. It is just that much worth your while.

 

[don Francisco]

The fluctuating pressure gauge is a good indicator of a cracked valve but a poor way to protect yourself. The best way to protect yourself is to develope and rely on good habits when setting up your equipment.

Since there is no logical reason to partially open a tank valve, train yourself to never do that. Only work with 2 positions; Closed or open (opened all the way, and backed off slightly).

If you decide to close a tank valve with the reg in place, (such as after testing the tank, but anticipating a long boat ride to the dive site) bleed the lines empty or down to less than 1,000psi. This way when you suit up and look at your gauge you'll see low or no air and be reminded to turn it back on. Leaving a fully charged regulator on a closed valve is just asking for a nasty surprise.

There are lots of little tricks and checks which will cover for bad habits, but in the long run nothing will protect you as well as developing good practices that are so ingrained that you'll do them without concious thought.

If you can't trust yourself to do things right in the first place, why would you trust yourself to do the recheck?

 

[ScubaSarus]

Aslo when you open your valve, I dont suggest backing it off 1/4 but just slightly. I see people overdoing this.

 

[herman]

Here are a couple of twist to the needle movement test (which I do every time). Most (all ??) air intergrated computers do not sample fast enought to detect a partly open valve so don't trust this test with an AI computer. One of the many reason I don't care for them. Also, on old J style valves, needle movement is normal when the valve in in the "dive" position.