Broken Fitting?

[Roadtrip]

Tobin,

My rig is a year old and I sent my reg in for annual service. When I picked it up today, the technician reported that the fitting on the end of the HP hose broke upon removal. They were happy that they were able to remove the nipple out of the first stage that remained. They felt that it was a poor fitting because they could see some corrosion had seeped through the plating. Would this be under warranty?

Thanks
Roadtrip

 

[cool_hardware52]

Tobin,

My rig is a year old and I sent my reg in for annual service. When I picked it up today, the technician reported that the fitting on the end of the HP hose broke upon removal. They were happy that they were able to remove the nipple out of the first stage that remained. They felt that it was a poor fitting because they could see some corrosion had seeped through the plating. Would this be under warranty?

Thanks
Roadtrip

We don't sell HP hoses, never have.

Tobin

 

[Roadtrip]

Sorry for my mistype..it is the Grey LP hose...with the knob on it. It came with my rig. I will post a photo tomorrow of the fitting. The technician wondered if it was an import fitting because he has rarely seen that happen.

thank you.

 

[cool_hardware52]

Sorry for my mistype..it is the Grey LP hose...with the knob on it. It came with my rig. I will post a photo tomorrow of the fitting. The technician wondered if it was an import fitting because he has rarely seen that happen.

thank you.

We've sold thousands of hoses using those exact fittings, with no other reported failures.

I have my doubts about a reg tech's ability to diagnose the source of the failure. These parts are nickle plated brass.

Fittings most often fail due to being over torqued at installation.

Tobin

 

[Roadtrip]

I can see corrosion in the middle of the field, indicating to me a plating problem. None of the other fittings had a corrosion problem and were all installed to the same torque. In my industry, Hazardous materials transportation, I find many differences in fittings, tankers, metallurgy and consistency in lots and materials. My concern with this failure would be it breaking under use at depth.

 

[cool_hardware52]

I can see corrosion in the middle of the field, indicating to me a plating problem. None of the other fittings had a corrosion problem and were all installed to the same torque. In my industry, Hazardous materials transportation, I find many differences in fittings, tankers, metallurgy and consistency in lots and materials.

These are nickle plated brass fittings. The threaded portion of this fitting is inside the oring seal. Even if there was no plating on the threads they should not corrode.

Are you suggesting a plating flaw in a brass fitting caused it to corrode to the point of failure in a year?

We have sold thousands of identical fittings, with no other reports of failure.

These fittings are subject to failure if over torqued at installation. DSS did not install this hose onto your first stage regulator.

DSS did not perform the regulator service either.

My concern with this failure would be it breaking under use at depth.

Such a failure could be hazardous, but your hose did not fail at depth. It "failed" while it was out of your hands, while being serviced by a "reg tech"

Your welcome to return the hose in question for inspection. I simply cannot comment further without seeing the parts.

Tobin

 

[Roadtrip]

Fair point regarding the Reg tech. Since I was not there observing, I have no way of knowing if it was not broken during re-assembly. However, I'm going to take it to my friend that is a materials engineer from NC State to take a good look at it and explain to my satisfaction the discoloration in the field of the material inside the thin layer of plating. This fitting is supposed to be solid brass with the plating? How much torque does it take to break that much solid brass? In foot pounds approximately?

 

[Divin'Papaw]

It's a hose. Replace it. You're talking maybe $25. They're disposable items. At least you got a year out of it. Sure it should have probably lasted longer assuming it was properly installed and properly cared for, but it didn't. You use them until they show undue wear and then replace them. If I were in NC I'd offer to give you one of the 4-5 I have in the gear box in my garage. Performing a material analysis on the fitting seems a bit over the top to me.

 

[cool_hardware52]

Fair point regarding the Reg tech. Since I was not there observing, I have no way of knowing if it was not broken during re-assembly. However, I'm going to take it to my friend that is a materials engineer from NC State to take a good look at it and explain to my satisfaction the discoloration in the field of the material inside the thin layer of plating. This fitting is supposed to be solid brass with the plating? How much torque does it take to break that much solid brass? In foot pounds approximately?

Most parts of scuba regulators are brass, including all the hose fittings I've ever encountered.

These fittings are machined from brass bar stock, most likely on a high production multi spindle lathe.

They are typically electroless nickel plated.

If these fitting had NO plating they would of course turn green, and produce a bit of Verdigris.

For corrosion to lead to the failure of the 3/8 x 24 male threads would be remarkable.

OTOH, impacts to the reg / hose can break fittings, such as tank falling over with a eg attached, as can over torquing during assembly.

Oring sealed fitting require very little torque, hand tight + a small bit more.

Today I twisted off one of the fittings we use, and one on a Scuba Pro hose, and one on a Poseidon hose.

All failed with the application of a 6 inch cresent wrench turned with one hand.

A failure due to fracture, i.e. impact or over torque, will present differently from a part that corroded through.

Tobin

 

[dumpsterDiver]

.....My concern with this failure would be it breaking under use at depth.

You should plan all your dives assuming that a fitting like that WILL fail underwater. I do.