Filling a BC manually vs. with tank?

[skippy31]

With regard to the free flowing in ice water. Based on the poster who refuses to believe it can happen I did a quick survey on our Canadian forum. Inside of an hour or two I had 3 people come back and indicate they had inflator free flow issues multiple times over the years.

Keep in mind we dive in ice water for months of the year here, so there is plenty of opportunity for it to happen.

Thread is here for the non believers.

3091-Power-Inflator-Free-Flow | Technical-Diving-Discussion

Feel free to debate it with the guys there if you still choose not to believe.

Mat.

 

[Thalassamania]

Mat,

I hear from some people who had power inflators fail. I hear they blame it on the cold. All I'm asking for is evidence, either actual or theoretical, and I have neither. Please add to the facts that I posted or come up with an engineering explanation as to how such an event might have occurred, otherwise I feel my opinion on the subject and my failure mode analysis must stand. We are not looking to find out who is right and who is wrong, that's irrelevant, what we want to know is what happened and how. If they'd like to come here and add to what we know, please extend my invitation to them to do so, but I feel that it would be inappropriate to move a thread that started here to a different board where our membership would not be the most direct beneficiary.

 

[CompuDude]

I don't manually inflate unless there is a need, usually due to an emergency of some sort. (stuck inflator, etc.)

Just last week, I manually inflated my wing for an entire dive, probably for the first time ever. (I'm not counting skills demonstrations while teaching) My [considerably less-experienced] buddy managed to forget his drysuit hose, since he had been diving wet for some time. I hooked him up with the DS hose from my regs instead, connected my LP inflator hose to my drysuit, and inflated manually. Worked just fine.

I prefer not to inflate manually, however, not so much because of issues with salt water (TC's concern), but more issues of bacteria getting into the wing. The usual quick rinse doesn't necessarily cut it to avoid wings with nastiness growing in it... I go for the capful of mouthwash in the rinse water to be sure. But frankly, that's more hassle than I want to deal with on a regular basis.

 

[skippy31]

Mat,

I hear from some people who had power inflators fail. I hear they blame it on the cold. All I'm asking for is evidence, either actual or theoretical, and I have neither. Please add to the facts that I posted or come up with an engineering explanation as to how such an event might have occurred, otherwise I feel my opinion on the subject and my failure mode analysis must stand. We are not looking to find out who is right and who is wrong, that's irrelevant, what we want to know is what happened and how. If they'd like to come here and add to what we know, please extend my invitation to them to do so, but I feel that it would be inappropriate to move a thread that started here to a different board where our membership would not be the most direct beneficiary.

It's interesting to note that I have not once had a free flow in warm water conditions (other than minor leaks due to the o-ring). I'll ask the question on our forum again to find out how many have had their inflators fail in warm water conditions as opposed to cold. I'm pretty sure the consensus in my neck of the woods is that the free flows are caused by the cold, but I'll put the question out there again.

Mat.

 

[peret]

I didn't read the whole tread but I don't get it...
If you blow the BCD from the tank or from your langs....what's the difference? The source of the air is the same: Your tank! So except adding more trouble there is no reason to do that except equipment failures.

 

[GA Under Water]

I didn't read the whole tread but I don't get it...
If you blow the BCD from the tank or from your langs....what's the difference? The source of the air is the same: Your tank! So except adding more trouble there is no reason to do that except equipment failures.

If you use air from your lungs you are recycling used air as a buoyancy tool not just exhaling it out into the water. Using the power inflater is using perfectly breathable air to fill a BC that through debates on here we have gleaned, carry bacteria and you don't want to breath that air anymore. In the end you save air in the tank, which makes less to refill which uses less compressor energy requiring less maintenance, and on down the line. WOW manually filling your BC could help save the planet, every little bit helps right?



Who'da thunk it GREEN DIVING

 

[Thalassamania]

It's interesting to note that I have not once had a free flow in warm water conditions (other than minor leaks due to the o-ring). I'll ask the question on our forum again to find out how many have had their inflators fail in warm water conditions as opposed to cold. I'm pretty sure the consensus in my neck of the woods is that the free flows are caused by the cold, but I'll put the question out there again.

Mat.

I've done hundreds of dives north of the Arctic circle ... never had an inflator (or for that matter a regulator either) freeze on me, but it could be a salt water (all my dives) vs. fresh water thing. There are other potential explanations for your collegues' free flows, but let's assume for the moment that they did occur as a result of a freeze up, can you propose an engineering explanation of the failure mode?

I didn't read the whole tread but I don't get it...
If you blow the BCD from the tank or from your langs....what's the difference? The source of the air is the same: Your tank! So except adding more trouble there is no reason to do that except equipment failures.

It's not a big deal, no right vs. wrong, it''s a small point but when you exhale from your lungs into the BC you do not change buoyancy, all you do is shift gas from one "bag" to another. The buoyancy change comes when you take your next breath, and if it is too great, as you feel yourself start to rise you can cut that inhalation short, or pull your dump, I find there's a little more fine control that way.

 

[Doc Harry]

It's very uncommon to fill your BC manually. It is an emergency procedure. Most people will never have to do it.

??????????

Uncommon, yes.

Emergency procedure? Definitely not.

 

[Nemrod]

Power inflators are an example of equipment dependency and unnecessary additional failure points that are easy to eliminate by eliminating the power inflator and a hose and all of the O rings and buttons and stuff that goes with it.

N, "N" 2 zen

 

[CompuDude]

Power inflators are an example of equipment dependency and unnecessary additional failure points that are easy to eliminate by eliminating the power inflator and a hose and all of the O rings and buttons and stuff that goes with it.

N, "N" 2 zen

Yeah! Back to horse collars and blow tubes, I say! Better yet, surface-supplied diving bells, forget all this compact gear that can fail!