Dear all, I have a headache and I need you help, with the following problem. I need to create excel sheet for the calculation (estimate) of the size of the orifice on the orifice plate that will produce a pressure reduction rate in pipeline at 0,5 bar per minute. It is not important to maintain pressure reduction rate during entire depressurization at 0,5 per minute, but it is essential that it starts at that level since it is maximum allowed. I would like to create a template in MS excel for this problem. Input data : Steel pipeline with outer diameter of 0,1524 meters (m), wall thickness 0,012 m, pipe length 100 m, at depth of 300 m (seawater), pipeline is filled with seawater and pressurized to 150 bar. Input data is just for reference and numbers are made up, I would like to know the methodology of solving this problem so I can create a template for calculation in the future.