a

Fractional annual depreciation on pipeline (dimensionless)

n

Exponent in pipe-cost equation $C \= X {\mathrm{D}}^n$(dimensionless)

b

Fractional annual maintenance on pipeline (dimensionless)

P

Installation cost of pump and motor ($/hp)

a'

Fractional annual depreciation on pumping installation (dimensionless)

Q

Fluid flow rate (ft³/s)

b'

Installed cost of pipeline, including fittings ($/ft)

S

Cross sectional area (ft²)

C

Inside pipe diameter (ft)

V

Velocity (ft/s)

D

Inside pipe diameter (ft)

X

Cost of 1 ft of 1 ft diameter pipe ($)

E

Combined fractional efficiency of pump and motor (dimensionless)

Y

Days of operation per year (at 24 hours per day)

F

Factor for installation and fitting

Z

Fractional rate of return of incremental investment (dimensionless)

K                

Energy cost delivered to the motor ($/kWh)

F

Factor for taxes and other expenses (dimensionless)

Le'

Factor for friction in fitting, equivalent length in pipe diameter per length of pipe (1/ft)

r

Flow density (lb/ft³)

M

$\frac{\left(a\'\+b\'\right) \left(E P\right)}{17.9 K Y}$

Factor to express cost of piping installation, in terms of yearly cost of power delivered to the fluid (dimensionless)

m

Fluid viscosity (cP)