Hi Sonic,<br>I do Chillers most of the time, I am assuming that they are of the Centrifugal or Reciprical type, and come flanged with 150#Flanges Raised Face, or Grooved Ends (ie Victaulic). You should use the 150Lb steel Pipe Selection with weldeable fittings A53 and Std.Wall Pipe A53 Gr.2B etc.<br>I wish I could see exactly what you are trying to do, then it would make it a lot easier for me to help you.<br>If you like send me your Email address and I will send you a AutoCad Ver.14<br>Dwg. of a recent job I have completeted.<br>Regards,<br> Tony<br>