Pipes - Fluid Flow Velocities
Imperial units
Fluid flow velocity in a circular pipe can be calculated with Imperial or American units as
v = 1.273 q / d2
= 0.4084 q gpm / d in 2(1)
where
v = velocity (ft/min, ft/s)
q = volume flow (ft3 /s, ft3 /min )
d = pipe inside diameter (ft)
q gpm = volume flow (US gal/min, gpm)
d in = pipe inside diameter (inches)
Online Pipe Velocity Calculator - Imperial Units
Dimensions: Steel Pipes schedule 40 & 80 , PVC and CPVC Pipes Schedule 40 & 80 , Copper Tubes and PEX Tubes
SI units
Fluid flow velocity in a circular pipe can be calculated with SI units as
v = 1.273 q / d2(2)
where
v = velocity (m/s)
q = volume flow (m3 /s)
d = pipe inside diameter (m)
Online Pipe Velocity Calculator - SI Units
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 in Pipes and Tubes
Fluid flow and pressure loss in pipe lines. Water and sewer systems. 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.
• Sizing of Steam and Condensate Pipes
Dimensions of steam and condensate pipe lines. Calculate pressure losses, recommended velocities, capacities 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 Densities
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.