Does anyone know what could cause a power inflator to suddenly inflate without being pressed?
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Does anyone know what could cause a power inflator to suddenly inflate without being pressed?
That would be the failure of one internal o-ring, but it should have been giving you indications before.
Dale
Sand or grit under the button can cause it to slowly inflate. A spring failure may also cause intermittent rapid inflation.
I've had one do it before, and on mine I think it was a failure of a spring. Unless I'm mistaken, mine was actually very similar to a schrader valve (tire stem valve). It's been years ago, but mine failed slowly. That is it just kept leaking into the bladder, no sudden inflation
I have had that happen to me too, the button got stuck on and I had to disconnect the hose asap, almost hit the ceiling hard.
I had this happen to me last year with my (then) brand new HOG wing. There is an internal O-ring that jambed against or between the button and the schrader valve. I've removed the offending seal and HOG has switched to a more standard inflator.... I've been meaning to ask Chris about a replacement but I fixed it myself and I doubt that it would be warrantable anyway. But the symptom was the same slow inflation and a lot of "WTF is going on with my bouyancy?????" "I know I can manage better than this"....... and some "why am I dumping air when I didn't add any???"
BTW: What brand of wing is it?
I had one freeze up on me a few years ago, in Florida. Adding air to wings on the surface. It was 17 degrees F. No problems in the water.
wrong size o ring after you bring it in the shop, had that happen years ago. Gueso ring was a little to big and it did not shut off after you use the inflate button. sometimes it worked sometimes it jammed.
I leave the backup inflator of my dual bladder unhooked but strapped to the inflator hose. In case I will need it I can connect it but don't have to fear that it will inflate accidentally.
Had one do it this past year with no warning, and not from sticking while inflating. Pulled it apart and an o-ring had gone.
Mine usually leak awhile, before they get to the point of uncontrollable inflation. I have learned to fix them before that happens :roll:
I recall having to learn that the hard way!Quote:
Originally Posted by FW
Thanks guys for all the useful information. Even the answers that don't apply to this problem have taught me stuff to do/look out for in the future.
I have been diving for 35 years and never had this happen before. Obviously I have been lucky until now, judging by the assortment of problems you have all had.
It is a Nomad EXP, about 18 months old (bought it new, so only me diving it) with maybe 100 dives on it. I have had no troubles with it before, no slow leaking or button problems at all. This came out of the blue and it inflated very fast and jammed me against the roof (only about 2 feet above when it started) with a fully inflated wing in the few seconds before I could get the post turned off (side mount).
I was exiting a sump after having de-kitted in a dry chamber which had a lot of silt and mud at the spot I got out. Everything had fine silt in it when I cleaned it at home later, so I am very suspicious that was involved in some way.
I disconnected the feed after turning the post off and then completed the dive without the feed connected. When I checked at home later the system worked fine. o rings look good and it is all working now. That's what worries me:?.
I'm sure I didn't push the button as it inflated ( you do this stuff on automatic and don't even realise you are sometimes) as it took me by totally by surprise and took a second to realise what was happening. If I had been using the inflator at the time I'm sure I would have made the connection instantly; that is: "button jammed on".
I had just done a sharp, 180 degree, turn, as I had been fixing some line and faced into the current to do that, but the way out was downstream. Is it possible that the inflator button hit some part of me as I swung and that, together with grit, jammed it on? How improbable is that:ele ?
That is as good a guese as any. We are glad you are OK. Imagine if that had happened in deep open water, or a deep pit inside a cave.Quote:
Originally Posted by speleocrone
I've trained for this scenario, at least for OW tri-mix, you can disconnect the inflator and dump the wing before you lose much depth at all, for me the greater danger was with two 130's and a deco bottle, I'd drop like a rock if I wasn't careful on how much I dumped.Quote:
Originally Posted by FW
It reminds me of the night I was driving a patrol car and smelled pepper spray... It only took a second to realize it was discharging from my duty belt into my shirt... but the effect stayed with me quite awhile!
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I have imagined that. As it was happening actually. Having had this experience, at least if it happens again (heaven forbid), without a convenient nearby roof, I will react very quickly. I hope.Quote:
Originally Posted by FW
I think I'll practice that myself now. Nothing like a lucky escape to motivate training.Quote:
Originally Posted by a64pilot
Over the 12 years my wife and I have been diving, we have had more problems with LP inflator valves than any other piece of equipment. The most potentially interesting one was when Tracy's stuck on halfway around the deep circuit at Twin. We flush them out, keep them clean, and we dive in fresh water much more than in salt, but they seem to be problematic. We keep a new one in our diving toolbox.
Mike
The ones that are on most wings are crap from China anyways. It does't matter how well you take care of them, Murphy will reach up and grab you at some point with them. I rebuild mine every 100 dives or so, basically whenever I service my regs. Coming from someone who works on inflators on a weekly basis, I have seen brand new ones stick or screw up more than older ones.
It can be a larger systems integration issue. For example I noted a diver I was mentoring who had an inflator hose length and inflator orientation such that the inflator could become stuck between her arm and the ridge made by the zipper across her chest. That was diagnosed after she reported auto inflates and then asking her what she was doing at the time followed by observing her in the water when she repeated her actions. Out of the water it was totally non-obvious but in the water when she reached across her chest with her left arm it was crystal clear what was happening. Rotating the inflator slightly to prevent the button from being pressed if it is trapped resolved the issue.
Similar issues can happen with dry suit inflators and cross chest straps.
Mechanically, schrader valves are fairly reliable but are not balanced so the inflators tend to lack sensitivity. Balanced inflators use a center balanced valve sealed on each end with an o-ring and they are more precise in operation, but both o-rings are susceptible to damage from sand, etc. so an annual rebuild is important but often skipped. What is worse, is that some (many) use non standard o-rings that shops may not have on hand. In that case mis sized o-rings can cause failures.
Some cheaper inflators are also not intended to be serviced at all but rather are considered to be disposable items.
Another common design issue is a return spring that is retained by the button. If it breaks off (or in some cases unscrews) then the spring ejects itself and the next time the remains of the button is pressed, it will start inflation but then won't stop when you stop pressing the button.
A general safety feature that is *supposed* to be built into a BC or wing is the ability to dump faster than you can inflate. If that is the case, you can immediately dump with one hand while you disconnect the inflator hose with the other. However in some cases this is accomplished with a restrictor in the inflator hose for a drysuit or wing so if the hose is changed (common in tech diving to get the right length) this safety feature is defeated. It's worth checking the stock hose to see if there is a restrictor in the inlet end of the hose. Whites for example did this with their dry suit inflator hoses.
I have a hose hat on the LP hose connected to all of my wing and drysuit inflators. Recreational single tank rig, doubles rig, warm water, cold water, they all have it. Disconnecting is fast and easy, and I have needed that speed on more than one occasion.
Mark Vlahos
I've had a continuous inflation experience with my nomad as well. In my case it directly related to sand intrusion following a tight squeeze which necessarily jammed my inflator into the sand during the restriction. For a while I doubted whether it was happening, as it started out subtle. Messed with my mind a little! Now I know to be aware of the potential, and always disassemble and clean the parts after such an excursion. A fast inflate is scarier.
Some excellent information here guys. Thanks.
I had a power inflator come apart and fail( hose open) with parts spit into the water at 140 feet in Cozumel in open water. I shut down the right post, switched regulators and lived to tell the tale. It only takes about 2 minutes to drain twin 80's through the low pressure inlator hose. Stay crisp on your emergency procedures. It saved my life.
Just curious, why didn't you just disconnect the inflater hose. When I just started my open water training my dad pulled the hold the inflater button open trick, anyway I just disconnected it. He also pulled the turn of the tank off trick.