Me thinks that azam needs to revisit his university courses first......a thorough grasp on basic civil engineering principles + hydraulics and structural engineering are in order.

Suggest that you borrow "The Piping Handbook" and read the chapters on piping flexibility and stress analysis. Look at the references at the end of the chapter.

Then, visit the website www.coade.com and review the software available.

long lentghs of pipe will expand and contact with temperature changes. an above ground pipe can expand and contract by the pipe's ability to freely move. there are exceptions. pumping hot liquids e-g.

an underground pipe will have different expantion rates depending on the depth they're buried and temperature changes throughout the year.

buried pipe can't compensate for expantion without an expantion joint of some type. i've seen many types of pipe expansion joints. find on that best suited for your needs.

restrained pipe lines are exactly that. RESTRAINED. look the word up in the dictionary, or ask the freaky girl living down the street who'll never let you touch her.

go back to school.