Environmental Engineering Reference
In-Depth Information
TABLE 4.4
C
Factors
Type of Pipe
C
Factor
Asbestos cement
140
Brass
140
Brick sewer
100
Cast iron
10 years old
110
90
20 years old
Ductile iron (cement lined)
140
Concrete or concrete lined
Smooth, steel forms
Wooden forms
Rough
140
120
110
Copper
140
Fire hose (rubber lined)
135
Galvanized iron
120
Glass
140
Lead
130
Masonry conduit
130
Plastic
150
Steel
Coal-tar enamel lined
New unlined
Riveted
150
140
110
Tin
130
Vitrified
120
Wood stave
120
Source:
Adapted from Lindeburg, M.R.,
Civil
Engineering Reference Manual
, 4th ed.,
Professional Publications, San Carlos,
CA, 1986.
Reynold's number.
C
factor values have been established for various types of pipe
(see Table 4.4). Generally, the
C
factor decreases by one with each year of pipe age.
Flow for a newly designed system is often calculated with a
C
factor of 100, based on
averaging it over the life of the pipe system.
DID YOU KNOW?
A high
C
factor means a smooth pipe. A low
C
factor means a rough pipe.
