Resistance Coefficients of Fittings
Fitting

Nominal Pipe Size

2

3

4

6

8

10

12 and above

Resistance Coefficient K

Gate Valves

0.15

0.14

0.14

0.12

0.11

0.11

0.10
Elbow (r/d=2)

0.23

0.22

0.20

0.18

0.17

0.17

0.16
Swing Check Valve

1.9

1.8

1.7

1.5

1.4

1.4

1.3
           

 

  
Pipe Exit - Sharp or Rounded

1
               

Typical Hazen and Williams Friction Factors C
Type of Pipe

Steel

Concrete

Cast Iron

 

.

    
C Factor New or Smooth

130 - 150

120 - 150

130 - 150

        
C Factor Corroded or Rough

80

85

80

        
C Factor (Typical for Design)

110

120

100

    

Design min.

Design max
C Factor Range Recommended for Calculating Required Pump TDH      

 

 

min. 120

max.140