How to Calculate Steam Velocity

Gas Velocity Calculation
••• Image courtesy of

Steam is a powerful gas and an effective heating element. To be sure, steam-turned turbines produce approximately 86 percent of electric power in the United States. From turning turbines to heating radiators, for as useful as steam can be it is still a vapor powerful enough to explode pipes and cause serious burns. Calculating the velocity of steam enables plumbers and steamfitters to gauge the appropriate thickness of pipe through which to deliver this essential gas.

    The velocity of any gas, including steam, is a measure of the flow rate divided by the total area of the flow.

    Determine the rate of flow through a given duct or pipe. This is typically measured in feet per minute--or more conventionally as ACFM (Actual Cubic Feet per Minute).

    Calculating ACFM requires having accurate measurements for pressure, temperature and humidity of current air conditions. It is calculated using the following formula: ACFM = [Standard Absolute Air Pressure / (Actual Pressure - Saturation Pressure x Relative Humidity] (Ambient Temperature / Standard Temperature).

    Calculate the flow area. For ducts, this is the width multiplied by the height. For pipes it is the height of the pipe multiplied by the width of the pipe. The flow area is noted as feet squared.

    Divide the rate of flow by the area of flow. The result should be recorded as feet per minute. This is the velocity of steam (or any gas for that matter).

    Things You'll Need

    • Paper
    • Pencil
    • Calculator

Related Articles

How to Calculate Cubic Feet Per Minute
How to Convert Steam Flow to Megawatts
The Uses of the Venturi Meter
How to Convert CV to GPM
How to Calculate Duct Airflow
What Is a Centrifugal Blower?
How to Calculate the Gas Loss in a Pipe
How to Calculate the Beta Ratio of a Flow Orifice
How to Solve for Volume
How to Calculate Cubic Feet Per Minute
What Units Does the Anemometer Measure In?
How to Calculate the Horsepower of a Compressor
Ball Valve Torque Calculation
How to Calculate Polytropic Efficiency
How to Convert Horsepower to Thrust
How to Size Gas Lines
How to Calculate Stack Exit Velocity
How to Calculate Saturation Pressure
How to Change Electrical Amps to Watts
How to Calculate CFM to MPH