Can I visually identify a pull dump on the inflator assembly?

[Raystafarian]

My OMS wing has one, I am a little embarassed that up until a week ago I didn't even know it was there, just happened to be reading a different thread about them and went and checked mine by orally inflating and pulling on inflator. Never had need for it so far, don't plan on using it.

My dive rite wing has one too, but there's no way to tell visually - I orally inflated mine and apparently it does have one.

 

[rsingler]

My dive rite wing has one too, but there's no way to tell visually - I orally inflated mine and apparently it does have one.

I think the key tipoff is the presence of vent holes. Elbows without a pull dump are just that: a curved or right angle pipe with a bcd connection at one end and the corrugated hose mount at the other. But if you can see a set of holes in the plastic, they likely vent a pull dump.
You can often feel a mechanical sensation as well, if you pull gently on the corrugated hose. But be careful - if there's no pull dump, there might also be no limiting cable inside.

 

[Raystafarian]

I think the key tipoff is the presence of vent holes. Elbows without a pull dump are just that: a curved or right angle pipe with a bcd connection at one end and the corrugated hose mount at the other. But if you can see a set of holes in the plastic, they likely vent a pull dump.
You can often feel a mechanical sensation as well, if you pull gently on the corrugated hose. But be careful - if there's no pull dump, there might also be no limiting cable inside.

Yeah there are some vents but I thought maybe that was over pressure relief, or whatever that's called.

 

[AustinV]

I’ve become accustomed to using the butt dump and raising the inflator. It’s good to know it’s there but I’ll stick to my normal methods of venting.

 

[WetSEAL]

I think you're talking about the ones that have a cable running through the inflator hose so when you pull on the hose it dumps.

There is no way to tell if they work or not, or even if they have one. Most BCD's have one these days but you can never tell if the cable is intact or even if it is attached or not. Pulling on the inflator is a good way to separate the inflator from the BCD, which will cause the BCD to be unable to hold air.

Maybe I'm not searching for the right thing, but I'm not finding anything on this. Correct me if I'm wrong, but is the idea behind this "inflator dump" basically a last resort dump of the BC bladder that happens if the inflator hose gets physically ripped off the BC? I guess I don't see why that's a good safety feature to have, because you still would have a ripcord that you could just to deflate the bladder if you wanted, and dumping all of the air at the very bottom of a dive could make it difficult to ascend if you don't have a lot of releasable weight.

I've seen failures of these things before, even during dives. In one case a diver pulled his inflator dump along a wall with a bottom depth of +/- 180m where it happened. He had the sense to dump his weights and return to the surface but it could have just as easily cost him his life.

Whoa...so his BC inflator ripped off, wrecking his BC, at a depth of 180 meters? That sounds really intense. I presume this was a professional deep dive with rebreathers?

 

[diversteve]

Pull the inflator itself - not the hose. If there is a cable it's attached to it and short enough to activate the dump without stressing the hose connections - or the inflator mount on the bladder..

I'd have to get mine out of storage and look but IIRC it has a flat opening at the back (top) of the assembly where the air escapes - not vent holes.

 

[Tom_Ivan]

Whoa...so his BC inflator ripped off, wrecking his BC, at a depth of 180 meters?

I read that as he was diving ABOVE 180m so could have ended up very deep if he hadn’t ditched his weights.

 

[divad]

Replace this

;

with this

 

[Dan]

It’s not on your inflator assembly, it’s on your bladder. Round plastic thing with a piece of string with a ball tied to the end. You pull the string to dump the air. You’ll definitely have one.

The ones that have pull dump option, have vent holes on the elbow to let the air out.

 

[rsingler]

Maybe I'm not searching for the right thing, but I'm not finding anything on this. Correct me if I'm wrong, but is the idea behind this "inflator dump" basically a last resort dump of the BC bladder that happens if the inflator hose gets physically ripped off the BC?

It's just another dump valve. Added by a manufacturer long ago as a "convenience" and then adopted by others. Since most bcd's have a right shoulder dump, they added this to be the left shoulder dump when you're in a position that puts the shoulders highest (e.g. initial descent below the surface). But as others have pointed out, despite it being "secured" by a cable, it is possible to literally pull the assembly off the bcd, in which case you have zero buoyancy and no way to restore it. Can also crack an old dry corrugated hose by repeated use. Most of us instructors advise against its use, although I'll admit that at one time I thought I was cool when everyone else was raising their corrugated hose up in the air to descend together, that I could just surreptitiously pull the inflator and the cable would let me descend without lifting my arm. Stupid. I don't use mine.

It dumps very quickly and is not really suitable for buoyancy adjustments while you're diving, though someone is bound to disagree.