Pipe freeze machine - new toy!

[WC1]

It's got to have something to push against to blow the pipe.

 

[bear]

What do you mean? I don’t understand.

 

[WC1]

As I understand it, water expands when it freezes and water is essentially not compressible. When a plug of ice forms in a pipe the lengths of pipe either side of the ice plug are expanded slightly to take up the pressure increase. If there is not enough length of pipe then there isn't enough "stretch" to accommodate the expansion and the pipe bursts.
If 2 ice plugs form near each other then as they grow toward each other there's not enough length of pipe to accommodate the expansion and the pipe bursts. Or if an ice plug forms near a closed valve or stop end again the pipe bursts as the plug grows toward the obstruction.
I only realised fairly recently that for frost to blow a pipe I think the water has to freeze at 2 points near each other or at a single point near a valve.
That's my take on it anyway...

 

[bear]

Ah I see. Highly doubt it was the case here as the burst in the picture is near where the jacket ended. It would be impossible for me to have two ice plugs forming either side of the burst.

 

[WC1]

Oh well, probably just one of those things that we'll never know...

 

[Stigster]

The ice plug compressed the water up against whatever was on that nut on the pipe, had nowhere else to go and burst through the thinnest part of the pipe wall. Thinner either from bending or just manufacturing variances. Even in a beautifully made piece of pipe, one place will be the thinnest and have to fail first when over-stressed.

 

[bear]

That but was on a tee so please explain where the water will / would expand too! Single pipe (frozen) to a tee (2 options)

 

[Stigster]

Well that's that particular aspect of my theory trashed!

I can only think that despite being frozen in a single jacket the pipe froze in two places separated by liquid water and the ice plug was not one continuous piece.

It's an unusual one that's for sure mate.

 

[bear]

Very. And I do doubt the “double ice plug” as where it burst was right at the bottom of the jacket. Not a place where is expect it to freeze. We’ll never know.