Page 104 - Applied Process Design for Chemical and Petrochemical Plants Volume I
P. 104
Fluid Flow 91
Y = 0.408 O/d2 = 0.0509 W/d$ d
Figure 2-22. Velocity of liquid in pipe. By per-
mission, Crane Co., Technical Paper #474
Engineering Div., 1957. Also see 1976 edition.
A?, = pressure drop across control valve Allowing 10% factor of safety, expected maximum
FM = friction pressure drop at maximum flow rate, psi increase in friction pressure drop allowance:
Friction loss or drop at higher flow rates than design: = 1.1 I(QdQDl2 - 11 (FD) (2-61)
At maximum flow rate, QM, the friction drop will
Increased pressure drop = [F, (QM / QD ) - F, 1,
become:
Ol- (2- 60)
FM = FD (Q~QD)' (2-62)
