Pipe Rack

Here's 7 pages of them. They don't even begin to cover the myriad of pipe types that are out there, not to mention you never said anything about how much, what length, what schedule, etc. _#75!

Don't know what a thumb rule is, myself.

Maybe you can find the definition here:

Books for thumb rules

Retain someone who know what he is doing. There are too many variables. Your question is too general and cannot be answered on a forum of this type.

would that be the right or left thumb rule.

What you seem to be interested in is structural pipe racks, which come in a wide variety of sizes and shapes.

Pipe racks are the major "highway" that connect the major process areas in a facility such as a refinery.

Try this website http://pip.org -STC01015 Structural Design Criteria

For examples, look here: http://www.safe-harbor.com/Product-Pipe-Racks.aspx

call your local steel suppier. he will be able to suggest the book you need, though the compulatations your seeking are a bit complicated. i would use common sense, then over design them.