This is an interesting area of inquiry. I am not sure that there any good formulas that can account for all the variables, such as average length of pipe runs between changes of direction, complexity of geometry, level of expertise of the pipefitters on the project, and adversity of working conditions.

There are various estimation programs that might allow one to add up the total number of fittings and valves in a piping system, and thereby arrive at an average of material and labor costs. But such averages might depart considerably from the particular conditions. You might web-search such terms as "piping estimation" and find some good information, or find some software on "project estimation."

About 25 years ago, I was involved in the reconstruction of an Aleutian Island seafood plant after a fire, basically as lead (actually only) pipefitter. I had access to a bender capable of one-shot or segment bending of up to 4" (100 mm) Schedule 80 pipe. Using a vector algebra method, I could calculate any bend in two arbitrary directions, plus any successive bend in any third arbitrary direction. Voila! No elbows and associated welds. We bent 21-foot (6 m) lengths of pipe any way needed, and just welded the ends together. This saved lots of time and money, but is not accounted for by any estimation program I know of.

Such considerations suggest the possibility of original research for new entrants into this field, perhaps yourself. I think there is much untapped potential in this trade/industry.

Thanks for the kind words, and GA for the specific citation.

Dear Tornado,

Thanks for sharing your interesting experience and kind suggestion.

Dear guest,

Do thank for your very useful citation. Being as a beginner, I have so many questions required to make clarify myself.

Hope you all could help me and guide me further.

Tks,

Kottu2.

I have a very comprehnsive spreadsheet used for this application and a PDF copy of the manual mentioned above. Send me you email address so I may foraward them to you.

Regards,

Stephen

Dear Stephen,

I would like to thank you in advance for your help and kindness.

By the way, I have already sent my e-mail address to you. I am looking forward to your mail.

Tks and Rgds,

Kotuu2.

Dear Sir,

Kindly also send me the same files.I too had a similar query.

My Mail ID is rukmani6@gmail.com

Thanks a lot for sharing your files

regards

rukmani