Quick Disconnect failure

[Silvic]

I had a quick disconnect nipple snap/breakoff while working the other day.





The equipment does have a fair amount of vibration but there are not really any side-loads applied to the QD fitting.



This was on the casedrain line not the primary flow lines.
Anyone ever have this happen to them?

 

[BeezFun]

It looks like two pieces that were welded together, and the weld failed because there's almost no penetration.. Seems odd to make that kind of a part in two pieces, so maybe I don't understand what I'm looking at. To answer your question, no, I've never seen a fitting break like that.

 

[Dave M7040]

I had a quick disconnect nipple snap/breakoff while working the other day.

View attachment 552214

View attachment 552215

The equipment does have a fair amount of vibration but there are not really any side-loads applied to the QD fitting.

View attachment 552213

This was on the casedrain line not the primary flow lines.
Anyone ever have this happen to them?

As I look at your photo of the collection of lines, my first impression is that the broken line was too short and as a result was exerting a bending load on the fitting. It is the smaller size of coupler and it broke at the smallest diameter part of the assembly which is what leads me to suspect fatigue from some side loading.

The coupling will release the line if given a sharp straight back pull but a pulling with a sideways component to the force will, over a long period of time, cause a fatigue failure.

Consider lengthening the hose.

Dave M7040

 

[Silvic]

As I look at your photo of the collection of lines, my first impression is that the broken line was too short and as a result was exerting a bending load on the fitting. It is the smaller size of coupler and it broke at the smallest diameter part of the assembly which is what leads me to suspect fatigue from some side loading.

The coupling will release the line if given a sharp straight back pull but a pulling with a sideways component to the force will, over a long period of time, cause a fatigue failure.

Consider lengthening the hose.

Dave M7040

Dave
Thanks for the input.

The line is not too short. What you are looking at is the hose and fitting with a cap installed to stop the fluid from leaking out. The nipple has been removed and is 3.5 inches longer that what you see. That case drain hose is actually a tiny bit too long and is tucked back in the chain with the 1 inch supply hoses.

In addition those Stucchi Series A FF QD will not release with a straight back pull. There are safeties on the release sleeve to prevent the release sleeve from accidentally being pushed back by brush and trees. I suspect that the vibration and harmonics from the mulching might have been at fault but most likely some foreign object hooked on the hose and put a lateral snap that caused it. I just have never seen that happen before.