Page 179 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

154 Applied Process Design for Chemical and Petrochemical Plants

Nomenclature F = Factor in Babcock’s steam flow equation
FD = Friction pressure loss (total) at design basis, for a
A = Internal cross-section area for flow, sq ft; or area of system, psi, for process equipment and piping, but
orifice, nozzle, or pipe, sq ft. excluding the control valve
a = Internal cross-section area for flow in pipe, sq. in. F, = Elevation factor for two-phase pipe line
a’ = Fractional opening of control valve, generally FM = Friction pressure loss (total) at maximum flow basis,
assumed at 60% = 0.60 for a system, psi
a, = Orifice area, sq in. F1 = Base friction factor, vacuum flow, Figure 2-43
a, = Velocity of propagation of elastic vibration in the F2 = Base friction factor, vacuum flow, Figure 2-43
discharge pipe ft/sec = 4660/ (1 + %,B,) f = Friction factor, Moody or “regular” Fanning, see
B = Base pressure drop for control valve from manufac- Note Figure 2-3
turer, psi fT = Turbulent friction factor, See Table 2-2
B, = Ratio of pipe diameter (ID) to wall thickness fg = Moody or “regular” Fanning Friction for gas flow
C = Condensate, lbs/hr (Equation 2-133); or for pipe, fTp = Two-phase friction for wave flow
Williams and Hazen constant for pipe roughness,
(see Cameron Table 2-22 and Figure 2-24); or flow (l/Q1’* = Gas transmission factor, or sometimes termed effi-
coefficient for sharp edged orifices ciency factor, see Table 2-15, f = Fanning friction
factor
C’ = Flow Coefficient for orifices and nozzles which equal
the discharge coefficient corrected for velocity of G = Mass flow rate of gas phase, pounds per hour per
approach = Cd/ (1 - p4) ‘I2 square foot of total pipe cross-section area
G’ = Mass rate, lbs/(sec) (sq ft cross section)
C’ = C for Figures 2-17 and 2-18
GPM = Gallons per minute flow
C’ = c’ = Orifice flow coefficient
g = Acceleration of gravity, 32.2 ft/(sec)2
Cd = Discharge coefficient for orifice and nozzles
H = Total heat, Btu/lb
CD1 = Diameter correction factor, vacuum flow, Figure 2-43
h = Average height of all vertical rises (or hills) in two-
CD2 = Diameter correction factor, vacuum flow, Figure 2-43
phase pipe line, ft
C, = Standard flow coefficient for valves; flow rate in or, h = Static head loss, ft of fluid flowing
gpm for 60°F water with 1.0 psi pressure drop across
the valve, = Q { (p/62.4) (AP)}”‘ hl = Enthalpy of liquid at higher pressure, Btu/lb
C’, = Valve coefficient of flow, full open, from manufac- h2 = Enthalpy of liquid at lower or flash pressure, Btu/lb
turer’s tables h, = hL = Loss of static pressure head due to friction of fluid
CT1 = Temperature correction factor, vacuum flow, Figure flow, ft of liquid
2-43 h, = Enthalpy of liquid at supply steam pressure, Btu/lb
CT2 = Temperature correction factor, vacuum flow, Figure h, = Enthalpy of liquid at return line pressure, Btu/lb
2-43
h,, = Head at orifice, ft of liquid
C1 = Discharge factor from chart in Figure 2-31
h’L = Differential static head or pressure loss across flange
C2 = Size factor from Table 2-11, use with equation on taps when C or C’ values come from Figure 2-17 or
Figure 2-31 Figure 2-18, ft of fluid
cp/c, = Ratio of specific heat at constant pressure to that at h,,~h = Maximum pressure developed by hydraulic shock, ft
constant volume=k of water (water hammer)
D = Inside diameter of pipe, ft K = Resistance coefficient, or velocity head loss in equa-
DH = Hydraulic diameter, ft tion, h, = Kv2/2g
d = Inside diameter of pipe, in. = d, & = Orifice or nozzle discharge coefficient
=
de = Equivalent or reference pipe diameter, in. hS Ratio of elastic modulus of water to that of the
metal pipe material (water hammer)
dH = Hydraulic diameter, or equivalent diameter, in.
k = Ratio of specific heat, cp/c,
do = Orifice diameter, or nozzle opening, in.
L = Pipe, length, ft
do, = Diameter of a single line with the same delivery
capacity as that of individual parallel lines dl and dz Le = Equivalent length of line of one size referenced to
(lines of same length) another size, miles, (or feet)
d, = Inside diameter of pipe, in. Le, = Equivalent length of pipe plus equivalent length of
fittings, valves, etc., ft.
E = Gas transmission “efficiency” factor, varies with line
size and surface internal condition of pipe L, = Length of pipe, miles