How to calculate pipeline length without pressure drop data

  • Thread starter Amirul96
  • Start date
  • Tags Tags
    Length
4 replies · 2K views · last reply
Amirul96
Messages
9
Reaction score
0
Hi,

I want to ask how to calculate the length of pipeline..From what i have searched, one of the way to calculate it is from the equation of pressure drop. However, it seems i don't have info about the pipe length and pressure drop (it means i need to calculate it). Is it possible to calculate the pipe length without those two info?

As in the attachment are the type of parameter may related to calculate the length of pipeline

Regard,
Mirul
 
Attachments
  • Input data table for a gas pipeline: volumetric flowrate 721.51 kSm3/d (25.48 MMSCFD), molecular weight 16.88, viscosity 0.013 cP, Z 0.951, Cp/Cv 1.361, pressure 3101.33 kPaA (30 barg), temperature 55 °C, 8-inch pipe schedule 80, internal diameter 0.1937 m, absolute roughness 0.00005 m.
    Spreadsheet 1.PNG
    10.4 KB · Views: 240
  • Spreadsheet titled Detailed Calculation Results listing gas density, flowrate, friction factor, Reynolds number, velocity and unit pressure drop with their units and values.
    spreadsheet 2.PNG
    11.9 KB · Views: 263
  • Table of equivalent length factors for valves and fittings, listing type, factor, quantity and equivalent length in metres for ball, gate, globe, check, plug and butterfly valves, tee, elbow, bend and enlargement fittings.
    Capture.PNG
    14.3 KB · Views: 250
  • Table of equivalent lengths in metres for pipe fittings, including contraction, strainer, and nozzle entries, with a total equivalent length of 6.40 m and pipe straight length of 1332.96 m, total 1339.36 m.
    Capture 2.PNG
    7.8 KB · Views: 246

Discussion

Amirul96 said:
how to calculate the length of pipeline
Usually you are given the length of the pipeline as one of the first specifications. How can you not know how far you need to pipe your product?
 
  • Like
Likes   Reactions: jim mcnamara
Chestermiller said:
What are you actually trying to calculate, and what are you given?

i want to calculate the line friction and i believe in order to calculate it i need the length of pipeline.
Calculator output table showing pipe straight length 1332.96 m including 10% margin, total pipe length including fittings 1339.36 m, pressure drop 7.73 kPa/100m, and line friction pressure drop 103.5563 kPa.


On the other side, the input are gas flowrate, pressure, temperature, molecular weight, compressibility and viscosity. However, i really doubt molecular weight, compressibility and viscosity are input and need to be calculate too.
Table 4.1-3 Input Data for Line Sizing: six pipeline lines with gas flow rate in MMSCFD, min operating pressure 3000 kPag, temperature 55 C, and lean and rich compressibility, molecular weight and viscosity values.
 
Amirul96 said:
i want to calculate the line friction and i believe in order to calculate it i need the length of pipeline.
View attachment 266269

On the other side, the input are gas flowrate, pressure, temperature, molecular weight, compressibility and viscosity. However, i really doubt molecular weight, compressibility and viscosity are input and need to be calculate too.
View attachment 266270
What is your definition of the "pipe friction", the shear stress at the wall? Or is it the pressure gradient times the length of pipe?
 

Similar threads

Calculate Pipeline Pressurization Time: 2,355 ft, 20 psi, 20-inch Pipe
  • cwright
  • · Replies 4 ·
  • General Engineering
Replies
4