How to Calculate Flow Rate With Pipe Size and Pressure

Water pressure drives a pipe's flow.
••• Jupiterimages/Photos.com/Getty Images

A higher pressure drop acting on a pipe creates a higher flow rate. A wider pipe also produces a higher volumetric flow, and a shorter pipe lets a similar pressure drop provide a greater force. The final factor controlling a pipe's viscosity is the fluid's viscosity. This factor measures the fluid's thickness in poise, or dyne seconds per square centimeter. A thicker fluid flows more slowly under the same pressure.

    Square the pipe's radius. With a radius, for instance, of 0.05 meters, 0.05 ^ 2 = 0.0025.

    Multiply this answer by the pressure drop across the pipe, measured in pascals. With a pressure drop, for instance, of 80,000 pascals, 0.0025 x 80,000 = 200.

    Multiply the constant pi by the answer to Step 1: 3.142 x 0.0025 = 0.00785. This answer is the pipe's cross-sectional area.

    Multiply the area by the answer to Step 2: 0.00785 x 200 = 1.57.

    Multiply the pipe's length by 8. With a length, for instance, of 30 meters: 30 x 8 = 240.

    Multiply the answer to Step 5 by the fluid's viscosity. If the fluid is water, its viscosity is 0.01, so 240 x 0.01 = 2.4.

    Divide the answer to Step 4 by the answer to Step 6: 1.57 / 2.4 = 0.654. The pipe's flow rate is 0.654 cubic meters per second.

Related Articles

How to Size Gravity Drainage Piping
How to Convert CV to GPM
How to Calculate the Velocity of Water Through Pipes
How to Convert mm Hg to in Hg
How to Calculate Hydraulic Cylinder Tonnage
How to Calculate GPM from PSI for Water
How to Calculate Drum Volume
How to Convert KPa to Liters Per Minute
How to Calculate the Area of a Pipe
How to Read a Manometer
Flow Rate Vs. Pipe Size
How to Calculate Condensate Flow From AC Units
How to Calculate Density From Viscosity
How to Calculate the Area of a Curved Surface
How to Calculate the Volume of a Cylinder
How to Calculate the Fluid Flow Through a Hole in a...
Volume Vs. Mass Density
How to Find Volume in Meters Cubed
How to Calculate Gallons by Cubic Feet
How to Calculate Evaporator Sizing