I once specified/installed 8" ball valves for 80 deg F, 500 psig condensate and it was a disaster because the valves were infrequently opened/closed,i.e, once per year or less. With non-use, the balls rust and take a 'set' in the seat. When one tries to open/close them, they will break the valve...
Thanks muscog for starting this thought provoking thread. The truth is in a combination of what everyone has said. However, I would like to add one additional glaring contributing factor for the Big Easy catastrophe:
As stated in Time Magazine and ASCE publications, there were millions if not...
I have used directional drilling for gravity sanitary sewer pipes.
First, it is important to understand the distinction between directional boring and underground boring.
Gravity sanitary sewers cannot tolerate 'porpoising' or humps in the pipe. With conventional horizontal drilling, a strait...
