BCD Inflator Hose Blowing Off Vest Connection

[tursiops]

Yes the corrugated hose is attached with a zip tie as shown in the attached photo. It does not use the dive right elbow mentioned above however. Tugging hard on the hose does not budge it. It seems to be a secure connection when testing it by hand.

Given that the internal pressure of the BC bladder should only be a few PSI It's hard to imagine how enough pressure is building up in the system to blow this connection apart with a loud pop. Sure seems like high pressure is building in the corrugated hose or shoulder fitting and not making it to the bladder but I have no reasonable explanation on how that could possibly occur. Unless the output pressure/volume of the inflator mechanism spikes under certain circumstances?

Thanks,
Ross

In this picture, what came loose? The corrugated hose from the plastic fitting, or the plastic fitting from the bladder? I assume the cable-tie on there now was installed by your LDS after the fact?

 

[RossBCO]

Looks like a hex (or octagon) -shaped flange nut. Have you tried unscrewing and tightening it?

I just unscrewed it and tightened it back down. It was very tight, so I had to use vise grips to loosen it initially. Nothing obvious in the connection that would indicate a problem.

In this picture, what came loose? The corrugated hose from the plastic fitting, or the plastic fitting from the bladder? I assume the cable-tie on there now was installed by your LDS after the fact?

The corrugated hose blew off the plastic fitting. The elbow itself was still attached as it should be. When this problem has occurred the cable tie has remained attached to the hose and the hose was reattached by shoving it back onto the elbow. I honestly don't know if the LDS replaced that cable tie or not.

Can't really tell how the elbow itself is designed. It's obviously not venting the entire 1 in diameter hose directly into the bladder. Is that a valve or more likely just a constriction to reduce the max volume of air that could enter the bladder?

Thanks,
Ross

 

[J-Vo]

I can see an unlikely scenario where the pull dump valve is stuck, so the corrugated hose got overpressure. In this case a good rinse and soak should take care of it.

My best guess, the original zip tie slipped/broke, then the replacement wasn't installed well. You did replace it after the first incident?

BTW: Every BCD in my garage has two zip ties on both ends of the corrugated hose.

 

[Eric Sedletzky]

It looks like that corrugated hose to BC bladder connection is a pull dump correct?
It’s probably reverse blocking somehow and building pressure in the corrugated hose with nowhere for the pressure to go as you come up. It blows off the hose at that connection because that’s the weakest link.
I would get rid of that whole mess and get a standard generic full manual style available from Trident (provided the threads are the same) and go with that.
Those pull dumps are a known failure point and while they are convenient for a nice vertical elevator descent they are extra fluff that you don’t really need.

 

[RossBCO]

I can see an unlikely scenario where the pull dump valve is stuck, so the corrugated hose got overpressure. In this case a good rinse and soak should take care of it.

My best guess, the original zip tie slipped/broke, then the replacement wasn't installed well. You did replace it after the first incident?

BTW: Every BCD in my garage has two zip ties on both ends of the corrugated hose.

It's definitely possible that the zip tie wasn't installed securely. I did give it several good hard tugs and it wouldn't budge though, so it seemed solid enough when testing by hand. The double zip tie on the corrugated hose idea makes a lot of sense.

It looks like that corrugated hose to BC bladder connection is a pull dump correct?
It’s probably reverse blocking somehow and building pressure in the corrugated hose with nowhere for the pressure to go as you come up. It blows off the hose at that connection because that’s the weakest link.
I would get rid of that whole mess and get a standard generic full manual style available from Trident (provided the threads are the same) and go with that.
Those pull dumps are a known failure point and while they are convenient for a nice vertical elevator descent they are extra fluff that you don’t really need.

I think the idea that you both separately suggested that the pull dump valve is glitching probably makes the most sense.

Based on the advice above and previous advice from tursiops and rongoodman
I have ordered a new complete inflator assembly/shoulder fitting from Cressi. It's interesting that they seem to have redesigned it in the last 2 years as the new one includes an overpressure valve in the fitting as well. It's worth $110 to me for the peace of mind of not having to wonder if/when this issue will come up again.

It's a little frustrating that neither Cressi or the LDS seemed to treat this like a serious issue (or offered to cover it under warranty)

Thanks to everyone for your input and advice!

Ross

​

 

[Eric Sedletzky]

It's definitely possible that the zip tie wasn't installed securely. I did give it several good hard tugs and it wouldn't budge though, so it seemed solid enough when testing by hand. The double zip tie on the corrugated hose idea makes a lot of sense.



I think the idea that you both separately suggested that the pull dump valve is glitching probably makes the most sense.

Based on the advice above and previous advice from tursiops and rongoodman
I have ordered a new complete inflator assembly/shoulder fitting from Cressi. It's interesting that they seem to have redesigned it in the last 2 years as the new one includes an overpressure valve in the fitting as well. It's worth $110 to me for the peace of mind of not having to wonder if/when this issue will come up again.

It's a little frustrating that neither Cressi or the LDS seemed to treat this like a serious issue (or offered to cover it under warranty)

Thanks to everyone for your input and advice!

Ross

​

Strange they didn’t cover it under warranty?
The LDS probably won’t cover it if they are not backed up by the manufacturer who would cover them. No LDS likes to be hung out to dry. If a manufacturer did that to me I’d drop their product line instantly. It seems like there are scuba manufacturers that don’t want to deal with problems or flat out deny that problems exist, but then they will secretly do a fix. So they know about stuff, they just don’t want to lose money dealing with it.
And yeah, it could potentially be a huge problem.
The smart manufacturers own the problem right away and know how to keep customers.
Would you buy Another one those BC’s in the future knowing the “warranty“ is pretty much non existent, or would you shop around for something else?

 

[RossBCO]

Strange they didn’t cover it under warranty?
The LDS probably won’t cover it if they are not backed up by the manufacturer who would cover them. No LDS likes to be hung out to dry. If a manufacturer did that to me I’d drop their product line instantly. It seems like there are scuba manufacturers that don’t want to deal with problems or flat out deny that problems exist, but then they will secretly do a fix. So they know about stuff, they just don’t want to lose money dealing with it.
And yeah, it could potentially be a huge problem.
The smart manufacturers own the problem right away and know how to keep customers.
Would you buy Another one those BC’s in the future knowing the “warranty“ is pretty much non existent, or would you shop around for something else?

Sorry I didn't really mean to turn this into a complaint about warranty support. Long story shorti(sh), the LDS couldn't recreate the problem so basically said "Take it to the pool and see what happens" in spite of being aware the issue occurred 3-4 times over 2 different trips. In a separate conversation with Cressi, they took the easy out of "You need to pay for the annual BC service" which the LDS said they were unable to do in the 3 weeks before my upcoming trip. (Part of that is obviously on me for not taking the BC in soon after the end of the last trip.) Given the first incident of the problem occurred when the BC was a month old, that seemed like an unlikely solution anyway. If my LDS had gone to Cressi saying "we would like to replace the inflator under warranty", how would that have played out?

I just felt like I was caught between the 2 with neither side willing to make the call of "we'll take the $100 hit in spite of not being able to recreate the problem " to ensure the safety and happiness of the end customer. Intermittent problems are definitely a hassle.... Can't exactly give everyone that comes into the dealership complaining of a rattling under the dash a new car right? Overall the LDS has been really good to work with, generous with pool time etc so I'm sticking with them, but you are right .... when it comes time to replace this BC, I will probably be switching to another brand.

Thanks,
Ross

 

[Eric Sedletzky]

I doubt an annual service would have caught that problem. They would have to have some prior knowledge of that being an issue in order to look for it, and it sounds like they had no clue. But then think about all the gear they sell and different brands to keep up with. You really can’t blame the LDS.