I am trying to calculate the SCFM of helium through five feet of SS tubing (1/4" OD x .035" wall). The helium would be flowing from a pressure vessel at 250 psig, through a pressure regulator set to 4psi, and into a compressor crankcase. What, if any, other information is required to calculate the SCFM? Once I have all of the info needed, how do I calculate it? I appreciate the help!