LP Miflex hose failure

[lommnb]

My Miflex inflator hose failed this weekend, did not blow out as the HP ones did, it actually stopped delivering air to the wing. I checked checked the inflator valve and corrugated hose connection at the wing looking for blockage and found nothing. Then changed the hose to a standard rubbed one and presto.

I cut the hose with my shears and actuated the little schrader valve inside, it seemed to function properly. It doesn't appear the hose is collapsing internally but I cannot find another failure point.

 

[Bubbletrubble]

I cut the hose with my shears and actuated the little schrader valve inside, it seemed to function properly. It doesn't appear the hose is collapsing internally but I cannot find another failure point.

I don't think I would have chosen to cut the hose without first changing the Schrader valve or taking a look inside the LP port. You could have also tried pressurizing the hose without a Schrader valve installed. Alternatively, with the old Schrader valve in place and the inflater hose pressurized but not attached to the male QD-post on the power inflater, you could have attempted actuating the Schrader valve manually with a screwdriver.

Schrader valves are so cheap that it seems kind of silly to have skipped these troubleshooting steps, given an LP inflater hose that doesn't allow air to flow into the power inflater assembly.

Lastly, since you've hacked the hose, you're probably going to have a hard time getting XS Scuba to replace it under warranty.

 

[Bradive]

My buddies hp miflex hose failed while swimming on the surface. The hose blew up midway between the fittings. It shreadded the hose and was pretty alarming. The hose had 12 dives on it and had no visible signs of wear. We were using 3000 psi tanks. We have 9 of these between our two families and none of the others have had issues yet. I am interested to hear how many other people have had failures.

 

[Blue Sparkle]

Welcome to SB, Bradive

My buddies hp miflex hose failed while swimming on the surface.... I am interested to hear how many other people have had failures.

While this thread is addressing an LP hose problem, there are quite a few past threads (here on SB and elsewhere) discussing the Miflex HP hoses/failures.

********

Edited to add: Here are a few threads on the HP hose, for example. I found them by typing miflex hp hose site:scubaboard.com into a Google search box.

http://www.scubaboard.com/forums/ge...-miflex-hp-hose-woes-scratch-another-one.html

http://www.scubaboard.com/forums/ge...scussions/362846-miflex-hp-failure-again.html

http://www.scubaboard.com/forums/regulators/364233-miflex-hp-bursting.html

http://www.scubaboard.com/forums/xs-scuba/343500-miflex-hp-blowout-eeek.html

http://www.scubaboard.com/forums/regulators/359480-how-miflex-hp-ruined-my-dive.html

One note: There are two "generations" of Miflex HP hoses, to my knowledge. The first one has exposed metal ferrules at either end of the braided hose section, whereas the second has molded black plastic (rubber?) strain relief covering the ferrules (no metal shows). It has been awhile since I've kept track of these threads, so I may be wrong on this point: But if I remember correctly, people have still had some issues even with the second generation HP hose.

I had one (second generation, purchased June 2010) but I retired mine. I never had a blowout (although I did worry about it slightly), but there were other things I didn't really like about it.

One is that the thin hose with my SPG on the end of it would sort of "hang" when on the boat, putting a lot of pressure on the strain relief. I felt I had to put a lot of effort into relieving that (of course I always clip off the SPG when underway, but it took much more care/worry than, say, the rubber one I replaced it with).

The second is that with the Miflex HP hose, my SPG would not swivel once it was pressurized. So I always had to try to get it into just the right position (for reading while the dive was underway) when I pressurized it.

Neither of the above were insurmountable, but conversely, I couldn't really see any advantages that made even the slight hassle worthwhile. (Maybe there are some that I just never knew about.) Once I had a niggling worry about possible blowout, that put me over the edge and I ordered a rubber hose. At the same time I went from 24" to 26", which seems to be a slightly nicer length on me.

*****
And now, back to our regularly scheduled LP hose thread...

 

[DA Aquamaster]

Cutting the hose was really unfortunate as it makes diagnosing the problem extremely difficult.

There is a valid argument for cutting defective hoses to prevent them from being used by someone who is not aware of the fault, digs it out of the trash, etc - but the time to do that does not occur until after the flaw or failure mode has been determined.

In this case no one can learn anything from this "failure" as it is not known if it was the hose, the schrader valve, or dimensional incompatibilities between the hose fitting and inflator.

 

[vancouverdiver]

So with all equipment, one can expect maintenance and replacement of parts over time. The HP hoses have gotten a lot of press about failures in short order. However, I have not read a lot of instances of failing LP miflex hoses. I need to replace my rubber LP hose after 1.5 years, and I'm wondering if the LP miflex hose is more or less durable than the ol traditional rubber hose. Anyone else with the LP miflex hose?
I have a slight kink off the first stage as it routes from my right post to the bcd. Thanks.

 

[buddhasummer]

Welcome to SB, Bradive



While this thread is addressing an LP hose problem, there are quite a few past threads (here on SB and elsewhere) discussing the Miflex HP hoses/failures.

********

Edited to add: Here are a few threads on the HP hose, for example. I found them by typing miflex hp hose site:scubaboard.com into a Google search box.

http://www.scubaboard.com/forums/ge...-miflex-hp-hose-woes-scratch-another-one.html

http://www.scubaboard.com/forums/ge...scussions/362846-miflex-hp-failure-again.html

http://www.scubaboard.com/forums/regulators/364233-miflex-hp-bursting.html

http://www.scubaboard.com/forums/xs-scuba/343500-miflex-hp-blowout-eeek.html

http://www.scubaboard.com/forums/regulators/359480-how-miflex-hp-ruined-my-dive.html

One note: There are two "generations" of Miflex HP hoses, to my knowledge. The first one has exposed metal ferrules at either end of the braided hose section, whereas the second has molded black plastic (rubber?) strain relief covering the ferrules (no metal shows). It has been awhile since I've kept track of these threads, so I may be wrong on this point: But if I remember correctly, people have still had some issues even with the second generation HP hose.

I had one (second generation, purchased June 2010) but I retired mine. I never had a blowout (although I did worry about it slightly), but there were other things I didn't really like about it.

One is that the thin hose with my SPG on the end of it would sort of "hang" when on the boat, putting a lot of pressure on the strain relief. I felt I had to put a lot of effort into relieving that (of course I always clip off the SPG when underway, but it took much more care/worry than, say, the rubber one I replaced it with).

The second is that with the Miflex HP hose, my SPG would not swivel once it was pressurized. So I always had to try to get it into just the right position (for reading while the dive was underway) when I pressurized it.

Neither of the above were insurmountable, but conversely, I couldn't really see any advantages that made even the slight hassle worthwhile. (Maybe there are some that I just never knew about.) Once I had a niggling worry about possible blowout, that put me over the edge and I ordered a rubber hose. At the same time I went from 24" to 26", which seems to be a slightly nicer length on me.

*****
And now, back to our regularly scheduled LP hose thread...

+1. I swapped out the HP Miflex to a Phantom and although hasn't blown it has became increasingly loose and floppy at SPG end. I think I will swap it out to a rubber one before it possibly blows, never had any issues with rubber.

Sorry back to LP thread...

 

[buddhasummer]

So with all equipment, one can expect maintenance and replacement of parts over time. The HP hoses have gotten a lot of press about failures in short order. However, I have not read a lot of instances of failing LP miflex hoses. I need to replace my rubber LP hose after 1.5 years, and I'm wondering if the LP miflex hose is more or less durable than the ol traditional rubber hose. Anyone else with the LP miflex hose?
I have a slight kink off the first stage as it routes from my right post to the bcd. Thanks.

I have been using the same Miflex LP hoses for around 5/6 years without any issues. I did coincidentally have an issue with the inflator hose leaking but this was solved by tightening the schrader valve.