Hi davidribeiro,
I have a spreadsheet which calculates optimum economic pipe dia.Its not written by me though.If you are interested,give me your e-mail id. I will send it to you.
regards,
sdprocess
Dear friend,
Pl. refer following document.I think it could be useful to you.
http://www.blackmer-mouvex.com/cbpdf/cb207.pdf
I am in a hurry.Gotta go.May be we will discuss it later.
Regard,
SDPROCESS