How to Size Gas Lines

Gas pipelines must be sized properly for process operations.
••• Jupiterimages/Photos.com/Getty Images

Sizing industrial gas lines correctly is critical for process operations as well as safety. If a gas line is not sized properly, fluid transfer could present a bottleneck in the process. General rule-of-thumb recommended velocity of fluid in a gas pipeline is 90-100 feet per second. This rate of flow is used to calculate the required pipe diameter and is used to determine and confirm the process volumetric flow requirements.

Things You'll Need

  • Pen
  • Paper
  • Calculator

    Determine the required volumetric flow rate based on process design conditions. Process engineers usually provide this information, but for demonstration purposes, assume there is a required gas flow rate of 100,000 cubic feet per hour at 200 psi (pounds per square inch).

    Determine the pipe diameter based on a recommended gas velocity of 95 feet per second. The velocity must be converted to feet per hour by multiplying the recommended velocity value by 3,600 (3,600 seconds equals one hour). This computes to 95 x 3,600 or 342,000 feet per hour.

    Divide the required volumetric flow rate (100,000 cubic feet per hour) by the velocity to determine the cross sectional area of the required corresponding pipe diameter. This is 100,000 divided by 342,000 which is 0.29 square feet.

    Determine the required internal pipe diameter from the cross sectional area. The calculation uses the formula of A = (d2)∏ / 4 where “A” is the cross sectional area, “d” is the internal diameter in feet and ∏ is Pi which is 3.1416. Since “A” is known, the formula becomes √(A x 4 / ∏) = d. Insert the numbers into the formula and calculate a diameter of 0.60 feet which can be rounded up to an internal diameter of 8 inches.

Related Articles

How to Find FWHM
How to Calculate Heat Loss During Pipeline Depressurization
How to Pressurize Natural Gas Pipelines for Leak Detection
How to Calculate Duct Airflow
How to Calculate Steam Velocity
How to Solve for Volume
How to Find Partial Pressures
How to Figure the Weight of a Steel Tank
How to Convert Fluid Ounces of Water to Weight
How to Size a Pneumatic Cylinder
How to Calculate CFM to MPH
How to Calculate the Beta Ratio of a Flow Orifice
How to Calculate the Temperature Drop Due to a Pressure...
How to Interpret a Student's T-Test Results
How to Calculate Polytropic Efficiency
How Does a Check Valve Work?
Volume Vs. Mass Density
How to Calculate Volume at STP

Dont Go!

We Have More Great Sciencing Articles!