Pipe Line Hydraulic Pipe Line Hydraulic CalculationCalculation

By: By:

M. KhosravyM. Khosravy

An Example !An Example !

• A pipeline has 4 segments as A pipeline has 4 segments as follow:follow:

Segment No. Length (Km) Elevation (+m) Temp (ºC)

1 15 20 502 20 40 303 50 10 404 15 0 20

Question #1Question #1

• If the pipe diameter and inlet/outlet If the pipe diameter and inlet/outlet pressure are known, what is the flow pressure are known, what is the flow velocity of natural gas in it?velocity of natural gas in it?

Outside diameter Do 52 Inches

Wall thickness t 0.25 Inches

Inside diameter Di 51.5 inches

Inlet pressure P1 1152 Psi

Inlet temperature T1 50 ºC

Outlet pressure P2 883 Psi

Outlet temperature T2 20 ºC

The Solution is :The Solution is :

Q(SCF/D) 2,415,957,168 = 68.41 MMSCM/Day

velocity 27.34 ft/s    

• If the pipe efficiency consider 92% and If the pipe efficiency consider 92% and effective roughness of 0.0018”.effective roughness of 0.0018”.

• The average erosion velocity is 59.2 ft/s The average erosion velocity is 59.2 ft/s so calculated velocity is OK.so calculated velocity is OK.

Question #2Question #2

• If we want to branch and use gas along If we want to branch and use gas along pipeline as follow, what is the suit pipe pipeline as follow, what is the suit pipe diameter according to desire pressure diameter according to desire pressure drop?drop?

Seg.No.

Distance(Km)

Flow Rate (MMSCM/D)

Inside Diameter (inches)

Elevation ΔH (+m)

Inlet Press. (Psi)

Outlet Press. (Psi)

Pav Psi

1 15 68.41 47.9556502 20 1152 1100 1126.2

2 20 68.41 44.3131359 40 1100 1000 1050.8

3 50 40 44.5039698 10 1000 900 950.88

4 15 30 44.1098344 0 900 883 891.53

Question #3Question #3

• If the flow rate and inlet pressure with If the flow rate and inlet pressure with pipe diameter are known for each pipe diameter are known for each segments, how we can calculate segments, how we can calculate pressure drop in each segments?pressure drop in each segments?

Seg. No.

Distance (Km)

Flow Rate (MMSCM/D)

Inside Diameter (inches)

Elevation ΔH (+m)

Inlet Press. (Psi)

Outlet Press. (Psi)

Pav Psi

Ave. Temp. (ºC)

1 15 68.41 47 20 1152 1094.2011123.34

8 50

2 20 68.41 47 40 1100 1025.9541063.40

7 30

3 50 40 47 10 1000 925.6103963.284

1 40

4 15 30 47 0 900 887.7554893.891

7 20

RPA Hydraulic Module RPA Hydraulic Module Calculate All Of Them !!!Calculate All Of Them !!!

It can be also help you to find It can be also help you to find thermo physical properties of thermo physical properties of natural gas.natural gas.

You can use any friction You can use any friction factor correlation in RPA!factor correlation in RPA!

1

f

.4 log

k

D

3.7065

1.2613

.Re f

k=Roughness in feet D=inside diameter in feet Re= Reynolds number

A 2.2.457 ln

7

Re

0.9.0.27k

D

16

A 337530

Re

16

k=Roughness in feet D=inside diameter in feet Re= Reynolds number

f .88

Re

12 1

A 2 A 3

3

2

1

12

A 4

k

D

1.1098

2.8257

7.149

Re

0.8981

f .1

.4 log

k

D

3.7065.5.0452

Relog A 4

2

4 k=Roughness in feet D=inside diameter in feet Re= Reynolds number

Thank You for Thank You for Your AttentionYour Attention