Quincy Shipyard barge cracking failure

Brass heating pipes (3" dia, Dowtherm-heated) inside heavy-crude barges; stress corrosion cracking traced to rinse-water pH of 2.3. Recommendation: change rinse water weekly or daily, with pH monitoring.

You have to actually change your deionized water sometimes. You're in the Coast Guard, right? You have to qualify ships. One of my first consulting jobs, when Quincy Shipyard was still in operation — I got a call because they were building some barges to transport a very heavy crude oil. They had to put some heating pipes in there so they could heat it up to pump it back out of the barge. They can pump it into the barge when it was warm — maybe it's number six fuel oil. Number six fuel oil, if you just let it come to room temperature, doesn't flow too well and doesn't pump very well. So they made these brass pipes like three-inch diameter and ran them through the inside of the barge, and you could run Dowtherm, which is a mineral oil type of heat transfer fluid.