Heat exchanger windows

admin

The other day I had to layout 4 windows (sight glasses) in a heat exchangers head. I found center by first marking up quarter points around the perimeter and then measuring across the face of the head from those points. Then I threw a piece of square tube with hole location marks on it, on top and measured down to the lip to make it equal. Then I clamped a piece of flatbar to one mark and leveled straight up, then clamped it to the tube. Then I could use a square on the tube and follow my marks to the head.  So, after going through all this, it got me to wondering if there were different methods. Have any of you had to do something similar? And how did you go about it?Common sense in an uncommon degree is what the world calls wisdom.