Pipe Roughness Coefficients Table Charts

Fluid Flow Table of Contents
Hydraulic and Pneumatic Knowledge

Please note that because of the variation in roughness in these materials depending on the source, the roughness values reported here have uncertainties ranging from ± 20 % for new wrought Iron to ± 70 % for riveted steel. A typical uncertainty in the roughness values can be assumed to be in the range ± − 30 -50 %.

This table lists the roughness Coefficients of Specific roughness, Hazen-Williams Coefficient and Manning Factor.

Pipe Material Roughness Coefficients
Pipe Material

Specific Roughness
Factor, • , mm (ft)

Hazen-Williams
Coefficient, C
Manning Factor, n
Steel, welded and seamless
0.061 (0.0002)
140
-
Steel, Sheet metal, new
5 x 10-2 (1.6 x 10-4)
Commercial, new
4.6 x 10-2 (1.5 x 10-4)
Steel, Riveted
3.0 (1 x 10-2)
Steel, Rusted
2.0 (7 x 10-3)
Stainless
2 x 10-3 (7 x 10-6)
Ductile Iron
0.061 (0.0002)
130
-
Iron, Cast new
2.6 x 10-1 (8.5 x 10-4)
Iron, Wrough, new
4.6 x 10-2 (1.5 x 10-4)
Iron, Galvanized, new
1.5 x 10-1 (5 x 10-4)
Iron, Asphalted, cast
1.2 x 10-1 (4 x 10-4)
Ductile Iron, asphalt coated
0.12 (0.0004)
130
0.013
Copper and Brass
0.61 (0.002)
140
0.010
Brass, new
2 x 10-3 (7 x 10-6)
Glass
0.0015 (0.000005)
140
-
Thermoplastics
0.0015 (0.000005)
140
-
Drawn Tubing
0.0015 (0.000005)
-
-
Concrete, smoothed
4 x 10-2 (1.3 x 10-4)
Concrete, Rough
2.0 (7 x 10-3)
Rubber, Smoothed
1 x 10-2 (3.3 x 10-5)
Wood, Stave
5 x 10-1 (1.6 x 10-3)
Sources:
Hydraulic Institute, Engineering Data Book.
Various vendor data compiled by SAIC, 1998
F.M. White, Fluid Mechanics, 7th edition

 

Surface Roughness for Various New Polyethylene Pipes (PE Pipes)

Type of Pipe
‘ε’ Absolute Roughness of Surface, ft
Values for
New Pipe
Reported
by Reference (1)
Values for New Pipe
and Recommended
Design Values Reported
by Reference (2)
Mean
Value
Recommended
Design Value
Riveted steel
0.03 - 0.003
–
–
Concrete
0.01 – 0.001
–
–
Wood stave
0.0003 – 0.0006
–
–
Cast Iron – Uncoated
0.00085
0.00074
0.00083
Cast Iron – Coated
–
0.00033
0.00042
Galvanized Iron
0.00050
0.00033
0.00042
Cast Iron – Asphalt Dipped
0.0004
–
–
Commercial Steel or Wrought Iron
0.00015
–
–
Drawn Tubing
0.000005
corresponds
to
“smooth pipe”
–
–
Uncoated Steel
–
0.00009
0.00013
Coated Steel
–
0.00018
0.00018
Uncoated Asbestos – Cement
–
Cement Mortar
Relined Pipes (Tate Process)
–
0.00167
0.00167
Smooth Pipes
“smooth pipe”
“smooth pipe”
PE and
other thermoplastics,
–
( 0.000005 feet)
(0.000005)
Brass, Glass and Lead)
(See Note)
(See Note)

Note: Pipes that have absolute roughness equal to or less than 0.000005 feet are considered to exhibit “smooth pipe” characteristics.

Relative roughness and friction factors for new, clean pipes for flow of 60°F (15.6°C) water (Hydraulic Institute Engineering Data Book, Reference 5) (1 meter 39.37 in = 3.28 ft).

Relative roughness and friction factors for new, clean pipes
Figiure 1, Click on image to enlage

Where:

f = friction factor
D = Diameter (inches)
ε / D = Relative Roughness
ε = Measure of pipe wall roughness in feet (meters)

References:

1. Swierzawski, Tadeusz J. (2000). Flow of Fluids, Chapter B8, Piping Handbook, 7th edition, Mohinder L. Nayyar, McGraw-Hill, New York, NY.
2. Lamont, Peter A. (1981, May). Common Pipe Flow Formulas Compared with the Theory of Roughness, Journal of the American Water Works Association, Denver, CO.

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