# Major flood



## 89plumbum (May 14, 2011)

5" flange blew apart at solder joint. 275psi High pressure line that held for 40 years, then at 1:00am that sucker just separated.


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## OpenSights (Mar 23, 2015)

Dang! So how deep did the solder flow? 1/4"? And it held that long! I see a lot of burst lines from freezing where the fitting blows right off and the solder only penetrated an eighth of an inch, but that's 1/2 and 3/4". 5" and 40 years!


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## 89plumbum (May 14, 2011)

You can see he did not pull his solder back correctly. Plus, it used to be a low pressure line until the city added PRVs which only after that they realized they had to install booster pumps. The fact that it was 50/50 solder may have played a roll in this also. I was hoping for some opinions on what you think of 50/50 on high pressure lines?


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## OpenSights (Mar 23, 2015)

I used 50/50 once just to see how it flowed, cut the joint. 3/4" joint. Didn't like the result, 95/5 was in use. Took some time before I got use to lead free. One supply house counter guy said they heard tinning flux works... not for me. 

Torch work was poor work for sure. I've only sweated up to 2" and the work with the torch and solder is very interesting to to me. Much different than 1/2-1".

As far as the strength of 50/50 and 95/5 or lead free, I can see there being a big difference in integrity between the three.


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## Tommy plumber (Feb 19, 2010)

That would be an interesting discussion with regard to 50/50 solder's ability to withstand high pressure. Lead is so soft, that my guess, and this is only a guess, is that the lead has to become fatigued after a while at a high pressure; sort of like when certain metals experience metal fatigue in aircraft and this has brought jetliners down in horrible crashes. 

Engineers learned about metal fatigue while studying airplane disasters. The aluminum fuselage would expand and contract flight after flight as the cabin was pressurized and this lead to metals failing. But when it happens at 30,000 feet with an aircraft travel 350 mph, it has devastating results.

Back to lead solder. My theory would need to be tested, but I'm thinking that lead would fail sooner than antimony or tin since it is such a soft metal.


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## Tommy plumber (Feb 19, 2010)

Stan, how did the repair go? Re-soldered and all was good?


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## Plumbus (Aug 4, 2008)

I've seen joints like that go that have been in for over 10 years.


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## 89plumbum (May 14, 2011)

Tommy plumber said:


> Stan, how did the repair go? Re-soldered and all was good?


Our service department actually fixed it. In desperation, the building wanted them to try to silver solder it back together but the plumber decided to try to locate some 5" victaulic couplings which he was able to do and had the water back on by noon. Unfortunately, they had to close the 42 story building for the day.


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## wyrickmech (Mar 16, 2013)

Standard soldering practices of the old trimmers around here was 95/5 with 50/50 cap.


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## rwh (Dec 17, 2014)

Bad joint. Huge flux pocket left in it. They will either look like that one, or a pie shape, with the void wider at the back of the joint. Have seen them fail even after many years. Good thing they didn't try brazing over old joint. Doesn't take very well with all the old solder on the joint.


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## 89plumbum (May 14, 2011)

Apparently there's good security footage of the line blowing while a security guard was walking by. Trying to get my hands on that!


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