Small holes in airline

[SlurrySeal]

This may seem wierd, but I just discovered small, almost micro, holes in the airline to my regulator. The hose was wet when I attached my first stage and I noticed little bubbles in a line down the tube towards my regulator. They almost look like they are supposed to be there because they are uniform and in a straight line down the hose.

My setup is brand new, only about 9 dives (I'm a fairly new diver as well, 26 dives). The hoses are Oceanic 250 psi, and the first and second stage are Oceanic. I've never noticed any bubbles when I've been diving, any clue as to what they are?

Thanks,
Lance

 

[SubMariner]

Regardless of the cause, those holes shouldn't be there, Slurry.

Take your gear back to the LDS where you bought it and have them replace the leaking hoses. Everything should still be under warranty, IMHO.

Bon chance,

~SubMariner~

 

[Uncle Pug]

Originally posted by SlurrySeal
I've never noticed any bubbles when I've been diving, any clue as to what they are?

Lance those little holes are in the outer casing and should the inner lining begin to leak and a seperation occur the escaping gas will exit all those little holes like a fizzy bubbler and keep your hose from rupturing and injuring you....

Sometimes, with some hoses... a little water that has gotten into those little holes will be squeezed out when you first turn your gas on. That is probably what you are seeing as *bubbles* and if you examine your other hoses you will no doubt find them there too.

But by all means ask your LDS

 

[SlurrySeal]

Thanks for the info!

I was a little worried when I saw the first hole, but after seeing the whole line of them down the tube I figured there was no way I could have caused it myself. Now I know.

-Lance

 

[tinman]

Tx Uncle P. You are not only entertaining but educational. Keep on bangin' those keys...I learn something everyday.

 

[SubMariner]

I don't profess to be an equipment tech, but since starting to dive over a decade ago I have never seen what slurry describes. Sorry, but it still sounds very strange to me.

No offense, eh?!

~SubMariner~

 

[Uncle Pug]

Originally posted by SubMariner
No offense, eh?!

Not all hoses have them...
Have you checked yours???

The cording holds the pressure of a hose while the inner core provides the seal to keep it from leaking... the outer covering is there to protect the cording. When the inner core develops a leak it passes right through the porous cording and since the outer cover is not strong enough to hold any pressure it bulges and then ruptures... but with the little perfs the outer cover just turns into a tiny-bubble wand.... it looks really cool UW.

 

[The Chairman]

The holes on the outside of the hose are intended as an early warning system... this I knew. The strength of a hose does NOT lie in the protective outer layer... that is to absorb abrasion. It is actually the inner weave (Kevlar/nylon/steel) that gives it it's strength. There are other materials used for this weave, but I forgot to write them down (so shoot me). The inner most layer is again of rubber or other non-permeable membrane and there are other interfaces in there as well which have better bonding characteristics to the various materials.

The holes (or in reality, pits) on the outside do NOT completely perforate the outer shell. No water should invade the shell/weave interface. They are like a bunch of burst discs in case the inner weave should rupture. It case of a leak, a rather long row of these holes will rupture, instead of creating an aneurism in the outer shell which might hide under a hose protector for a while. According to my rep, this does not mitigate a catastrophic failure; it only reveals the more common small leaks.

I have seen these holes for quite a while on both low pressure and high pressure hoses for various liquids/gasses. They are quite regular in nature and may look like they are "holding" bubbles. In all actuality, it is probably the surface tension of the air in those holes which causes them to stick there under water. Unless there is an active leak, there should be no rupture of the thin membrane at the bottom of the "pits".

Hope this helps, and my regards to Jorge for his invaluable insight into the situation.