gas flow formula

huangyhg

gas flow formula
do anyone recognizes the following gas flow formula (for air here)?
w (lbs/sec) = 6.30*cd* (d^2) *p1 /[(53.34*t)^0.5] * {3.5[(p2/p1)^1.429 - (p2/p1)^1.714]}^0.5
i would appreciate someone can point me to the source.  
i understand one from "crane":
qm' (scfm) = 678 *y *(d1^2)* c *{[deltap*p1'/(t1sg)]^0.5}
but they have gap and i do not know how to prove they are the same.
thank you in advance for your kind help.
that looks like one of the empirical heat transfer equations, but i don't have my heat and mass transfer book handy.  i'll look when i get home this evening if noone gets to it before then.
-kirby
hi kirby,
thank you.  i'm sorry that i forgot to mention they are gas flow equation through orifice.  "crane" means "crane co. - technical paper no. 410".  anyway, thank you for your kind help.