Just ran across a gas valve plugged with small, slightly rounded slivers of debris. They were pretty uniform in size and were mainly bunched up at the screened inlet. The preceding line was copper and had a drip leg that was 6 feet from the furnace,. The slightly rounded shape of the debris matches the curvature of the copper pipe so I am assuming the debris is from the 6 feet of copper pipe.
I have seen this twice before on one other furnace , where the plugging was 7 years apart.
Anyone have any ideas or experience on how this could happen?
For some time copper was being discouraged because of gas containing a significant amount of hydrogen sulfide . Some areas of distribution were worse than others . While it is discouraged for use with NG but is approved for LP I've seen black flakes in propane copper lines that will plug a screen .