Closed CHW loop solder joint leaks
Closed CHW loop solder joint leaks
(OP)
Have a Closed loop chilled water system, several solder joint failures resulting in leaks. Joints I'm pretty sure are typical lead free pipe solder. 30% propylene glycol solution.
Water chemistry sample:
pH: 11.00
Conductivity: 5,900 umhos/cm
Total Alkalinity: 15,000 mg/L as CaCO3
Calcium: below reporting limit
Total Hardness: 3.0 mg/L
My thoughts: pH seems high, but doesn't seem high enough to eat solder, although I'm not sure how solder interacts with propylene glycol and high pH solutions. Conductivity and Total Alkalinity are very high - for closed loops I'd think conductivity would be <1,000 or so.
Tried this post in the Chem. Eng. forum but no luck yet. Your thoughts/experiences are appreciated! CB
Water chemistry sample:
pH: 11.00
Conductivity: 5,900 umhos/cm
Total Alkalinity: 15,000 mg/L as CaCO3
Calcium: below reporting limit
Total Hardness: 3.0 mg/L
My thoughts: pH seems high, but doesn't seem high enough to eat solder, although I'm not sure how solder interacts with propylene glycol and high pH solutions. Conductivity and Total Alkalinity are very high - for closed loops I'd think conductivity would be <1,000 or so.
Tried this post in the Chem. Eng. forum but no luck yet. Your thoughts/experiences are appreciated! CB





RE: Closed CHW loop solder joint leaks
How long has the system been in service? Have you examined the failed joints to see what the mode of failure was?
On a recent project, we had a 25% failure rate on joints in a copper air system with lead-free joints. One of the fitters could not get a good joint reliably. We cut open half his joints, and most had < 50% solder coverage. All the failures happened within days, tho.
RE: Closed CHW loop solder joint leaks
RE: Closed CHW loop solder joint leaks
RE: Closed CHW loop solder joint leaks
I just put a response in the Chemical engineering section.
I did not, realise you had cross posted, and I just came across this post, after I had responded to the other one.
B.E.
RE: Closed CHW loop solder joint leaks