Equations Commonly used for Calculating Hydraulic Data for Gas Pipelines

Panhandle A

Panhandle B

Weymouth

Nomenclature for Panhandle Equations

Qb = Flow rate, SCFD

Pb = - Base pressure, psia

Tb = Base temperature, R

T _avg = Average gas termperature, R

P ₁ Inlet pressure, psia

P ₂ Outlet pressure, psia

G = Gas specific gravity (air = 1.0)

L = Line length, miles

Z = Average gas compressibility

D = Pipe inside diameter, in.

h ₂ = Elevation at terminus of line, ft

h ₁ = Elevation at origin of line, ft

P _avg = Average line pressure, psia

E = Efficiency factor

E = 1 for new pipe with no bends, fittings, or pipe diameter changes.

E = 0.95 for very good operating conditions, typically through first 12-28 months

E = 0.92 for average operating conditions

E = 0.85 for unfavorable operating conditions

Nomenclature for Weymouth Equation

Q = Flow rate, SCFD

Tb = Base temperature, R

Pb = Base pressure, psia

G = Gas specific gravity (air = l)

L = Line length, miles

T = Gas temperature, R

Z = Gas compressibility factor

D = Pipe inside diameter, in.

E = Efficiency factor. (See Panhandle nomenclature for suggested efficiency factors

Sample Calculations

Q = ?

G =0.6

T =100 F

L = 20 miles

P ₁ = 2,000 psia

P ₂ = 1,500 psia

Elevdiff= 100 ft

D = 4.026-in.

T _b