.........and that leads to the question "what were the reference documents for the internal Kellogg Manual? At what point did someone actually develop all this good design theory from basic statics and strength of materials (and when was it first put into print)? If you follow the trail back far enough (if you can find the trail) it takes you to Roark, Timoshinko and Hooke's law) and some of the olde traditional piping design stuff is really hard to assign to ANY owner. When we publish (or teach) we have some responsibility to assign credit for our sources but sometimes it is not possible. Maybe John Luf wrote all this stuff before I was born (?). I have been presenting piping design and analysis seminars for more than (gulp!) 30 years and when I look back to my original development material I can't find all the sources (but I did find some original drawings of Noah's ark). Some piping design information has been with us sooooo long that it can no longer be considered proprietary.

There have been some "rules of thumb" that I have seen in many corporations' "in-house training materials" that have been passed down from generation to generation. I have been told that "..well, we think that came from the old Kellogg book..." but upon investigation this was not the case.

This topic of trunnion design has taken me back into my olde basement archives (for your folks in Tejas, a basement is a dark little room found under most houses in Yankeeland) to try to find the original source of some of my design notes and I have found an old dusty blue 3-ring binder with the "Grinnell" name on it. I remembered in the mid to late '60s, Grinnell presented a training program for hanger and support design that I helped with. In the binder, there are 8 or 10 pages that focus upon "Grinnell Hanger Standards" 62 and 63. These pages present a step by step procedure for determining what specific (size, etc.) Grinnell pipe stanchion should be ordered with consideration of the size (and wall thickness) of the pipe to be supported, the load, the temperature, the pipe material, etc. They include tables of wall thickness correction factors, temperature correction factors, etc. It is all set up in nice neat tables and charts. Only one problem, there is NO disclosure of the underlying theory!! There are no references. So, use it if you want to, but let the designer beware. Now that I have found this stuff again, I will have to ask Anvil if they happened to inherit the Grinnell archives (let me see now, where did I put Dan Walsh's phone number?).

There just has to be some time limit on copyrights - when "ideas" fall into the public domain (...or else someone owes Matthew, Mark Luke and John a bunch of money).


Regards, John.