Ethylene Glycol for Heating

[PSP113]

We use ethylene glycol for our heat tracing. The boiler that we use for heating the glycol was re-tubed two years ago, and it just started leaking 3 months ago. Upon inspection, we found several tubes corroded around the area on the tube attached to the tube sheet(they're attached by rolling). We had an analysis done on the failed tubes and found a high level of Phosphorous, Potassium and Calcium in the corroded tubes. Does anyone have any ideas on sources of these metals? The boiler operated for almost 30 years before being re-tubed the first time, and nothing has changed in the operation since then, so I don't see why corrosion would set in so fast.

 

[ash9144]

Is the contaminant concentrated on inside or outside of tube?
Does your process consist of those compounds?

 

[Unotec]

Did you used a different water source? Are your softeners still good?

<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>

 

[PSP113]

The tubes are heated by a natural gas burner on the inside, and the glycol flows outside of the tubes. The corrosion is from the outside in. Our process does not include these compouds. The water source hasn't changed.

 

[ash9144]

This would be strange since you are heating the glycol but those compounds are fairly common in cooling water. Could you a process tube leak allowing cooling water into the EG.

Recently receive new shipment of EG?