Thanks for the input so far. It is a chilled water system for a building and is schedule 40 steel. i assume the normal post construction flushing and cleaning. I think its about 8 years old. There are no filters only strainers. A large one at the main pump and much smaller ones at each ahu 1/2"...
I will have to find out if there are any inhibitors in this system but it is a chilled water loop with glycol added. We get this fine black silt that clogs strainers in the sysytem. These are very small strainers in a 1/2 inch pipe that feeds a small ahu. Just trying to figure out what it could...
