Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

# Pipes - Fluid Flow Velocities

## Calculate fluid velocity and volume flow in pipes and tubes.

### Imperial units

Fluid flow velocity in a circular pipe can be calculated with Imperial or American units as

v = 1.273 q / d 2

= 0.4084 q gpm / d in 2 (1)

where

v = velocity (ft/min, ft/s)

q = volume flow (ft 3 /s, ft 3 /min )

d = pipe inside diameter (ft)

q gpm = volume flow (US gal/min, gpm)

d in = pipe inside diameter (inches)

### SI units

Fluid flow velocity in a circular pipe can be calculated with SI units as

v = 1.273 q / d 2 (2)

where

v = velocity (m/s)

q = volume flow (m 3 /s)

d = pipe inside diameter (m)

### Example - Flow Velocity in a Steel Pipe

60 US gal/min is flowing through a 4 inch schedule 80 steel pipe . The internal diameter of the pipe is 3.83 in . The velocity can be calculated as

v = 0.4085 ( 60 gal/min ) / (3.83 in) 2

= 1.7 ft/s

## Related Topics

• ### Fluid Flow and Pressure Loss

Pipe lines - fluid flow and pressure loss - water, sewer, steel pipes, pvc pipes, copper tubes and more.
• ### Fluid Mechanics

The study of fluids - liquids and gases. Involving velocity, pressure, density and temperature as functions of space and time.
• ### Pipe Sizing

Sizing of steam and condensate pipe lines - pressure loss, recommended velocity, capacity and more.

## Related Documents

• ### Boiling Fluids - Max Suction Flow Velocities

Recommended max suction flow velocity when pumping boiling fluids.
• ### Boiling Liquids - Max Pumping Flow Velocities

Recommended max flow velocity on the delivery (pressure) side when pumping boiling liquids.
• ### Copper Tubes - Maximum Water Velocities

Water velocity in a copper tube should not exceed certain limits to avoid erosion.
• ### Light Oil Pumping - Flow Velocities

Recommended max. flow velocities on the delivery side when pumping light oils.
• ### Pipe Line Velocities vs. Fluid

Typical fluid flow velocities for common liquids, gases and vapors.
• ### Slurry - Density

Calculate density of a slurry.
• ### Slurry Transports - Minimum Flow Velocities

Flow velocities in slurry transport systems to avoid settling of solids.
• ### Steel Pipes - Maximum Water Flow Capacities vs. Size

Maximum water flow capacities in steel pipes - pipe dimensions ranging 2 - 24 inches.
• ### Viscous Liquids - Max. Delivery Flow Velocities

Recommended max. flow velocities on delivery sides of pumps in viscous systems.
• ### Water - Max. Suction Flow Velocities vs. Pipe Size

Recommended max. water flow velocities on suction sides of pumps.
• ### Water Flow - Max. Delivery Velocities vs. Pipe Size

Recommended maximum flow velocities in water systems on the delivery side of the pump.
• ### Water Flow in Tubes - Reynolds Number

Reynolds number for clean cold water flow.
• ### Water Systems - Maximum Flow Velocities

Water velocities in pipes and tubes should not exceed certain limits.

## Search

Search is the most efficient way to navigate the Engineering ToolBox.

## Engineering ToolBox - SketchUp Extension - Online 3D modeling!

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

About the Engineering ToolBox!

We don't collect information from our users. More about

## Citation

• The Engineering ToolBox (2008). Pipes - Fluid Flow Velocities. [online] Available at: https://www.engineeringtoolbox.com/pipe-velocity-d_1096.html [Accessed Day Month Year].

Modify the access date according your visit.

12.8.9