Pipe Sizing

Hi to all,

pls refer below formula which is using for desingning for Natural gas pipe line

d=(1/10)*[(17.8* Qn2*dv)/P12-P22)]1/5

P1 6.11 Kg/Cm2 Absolute pressure

P2 = 5.911 Kg/Cm2

d is diameter in meter

dv is Density ration for NG (For NG = .75/1.293 =.58) Assumed SG of NG .75)

λ is friction factor ( 0.024)

K is compressibility factor (0.99=1)

l is in Km

Now pls suggest me what is the valuve of dv,λ and K in case of Propane gas.