black iron to copper pipe sizing capacity

[patico20]

hello, I'm currently studying for my G3 exam (September 15th) and can't for the life of me understand how to appropriately size pipe charts that go from black iron to copper. if anyone could lead me in the right direction that would be appreciated.

[Admin]

This should help,

https://www.hvactechgroup.com/hvacforum/index.php?topic=702.msg1860#msg1860