K Value of Fittings
K Value of Fittings
K Value of Fittings
Page 1 of 5
LD
1 1
2-3
K Value
Angle Valve
55 1.48 1.38 1.27 1.21 1.16 1.05 0.99 0.94 0.83 0.77 0.72
0.66
Angle Valve
150 4.05 3.75 3.45 3.30 3.15 2.85 2.70 2.55 2.25 2.10 1.95
1.80
Ball Valve
3 0.08 0.08 0.07 0.07 0.06 0.06 0.05 0.05 0.05 0.04 0.04
0.04
0.30
8 0.22 0.20 0.18 0.18 0.15 0.15 0.14 0.14 0.12 0.11 0.10
0.10
Butterfly Valve
Gate Valve
Globe Valve
4.4
4.1
90 2.43 2.25 2.07 1.98 1.89 1.71 1.62 1.53 1.35 1.26 1.17
1.08
18 0.48 0.45 0.41 0.40 0.38 0.34 0.32 0.31 0.27 0.25 0.23
0.22
Plug Valve 3-Way Thru-Flow 30 0.81 0.75 0.69 0.66 0.63 0.57 0.54 0.51 0.45 0.42 0.39
0.36
Standard Elbow
90 Bends,
Pipe Bends,
Flanged Elbows,
Butt-Welded
Elbows
5.8 5.1
4.8
90
30 0.81 0.75 0.69 0.66 0.63 0.57 0.54 0.51 0.45 0.42 0.39
0.36
45
16 0.43 0.40 0.37 0.35 0.34 0.30 0.29 0.27 0.24 0.22 0.21
0.19
long radius
90
16 0.43 0.40 0.37 0.35 0.34 0.30 0.29 0.27 0.24 0.22 0.21
0.19
50 1.35 1.25 1.15 1.10 1.05 0.95 0.90 0.85 0.75 0.70 0.65
0.60
20 0.54 0.50 0.46 0.44 0.42 0.38 0.36 0.34 0.30 0.28 0.26
0.24
60 1.62 1.50 1.38 1.32 1.26 1.14 1.08 1.02 0.90 0.84 0.78
0.72
r/d=1
20 0.54 0.50 0.46 0.44 0.42 0.38 0.36 0.34 0.30 0.28 0.26
0.24
r/d=2
12 0.32 0.30 0.28 0.26 0.25 0.23 0.22 0.20 0.18 0.17 0.16
0.14
r/d=3
12 0.32 0.30 0.28 0.26 0.25 0.23 0.22 0.20 0.18 0.17 0.16
0.14
r/d=4
14 0.38 0.35 0.32 0.31 0.29 0.27 0.25 0.24 0.21 0.20 0.18
0.17
r/d=6
17 0.46 0.43 0.39 0.37 0.36 0.32 0.31 0.29 0.26 0.24 0.22
0.20
r/d=8
24 0.65 0.60 0.55 0.53 0.50 0.46 0.43 0.41 0.36 0.34 0.31
0.29
r/d=10
30 0.81 0.75 0.69 0.66 0.63 0.57 0.54 0.51 0.45 0.42 0.39
0.36
r/d=12
34 0.92 0.85 0.78 0.75 0.71 0.65 0.61 0.58 0.51 0.48 0.44
0.41
r/d=14
38 1.03 0.95 0.87 0.84 0.80 0.72 0.68 0.65 0.57 0.53 0.49
0.46
r/d=16
42 1.13 1.05 0.97 0.92 0.88 0.80 0.76 0.71 0.63 0.59 0.55
0.50
r/d=18
45 1.24 1.15 1.06 1.01 0.97 0.87 0.83 0.78 0.69 0.64 0.60
0.55
6.1
Thru-Flow
Thru-
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Mitre Bends
Page 2 of 5
a=0
2 0.05 0.05 0.05 0.04 0.04 0.04 0.04 0.03 0.03 0.03 0.03
0.02
a=15
4 0.11 0.10 0.09 0.09 0.08 0.08 0.07 0.07 0.06 0.06 0.05
0.05
a=30
8 0.22 0.20 0.18 0.18 0.17 0.15 0.14 0.14 0.12 0.11 0.10
0.10
a=45
15 0.41 0.38 0.35 0.33 0.32 0.29 0.27 0.26 0.23 0.21 0.20
0.18
a=60
25 0.68 0.63 0.58 0.55 0.53 0.48 0.45 0.43 0.38 0.35 0.33
0.30
a=75
40 1.09 1.00 0.92 0.88 0.84 0.76 0.72 0.68 0.60 0.56 0.52
0.48
a=90
60 1.62 1.50 1.38 1.32 1.26 1.14 1.08 1.02 0.90 0.84 0.78
0.72
Fitting
Minimum
Velocity for
L/D Full Disc Lift
General Water
ft/sec ft/sec
1 1
2-3
K Value
100 35
4.40 2.70 2.50 2.30 2.20 2.10 1.90 1.80 1.70 1.50 1.40 1.30
1.20
50
6.06 1.40 1.30 1.20 1.10 1.10 1.00 0.90 0.90 0.75 0.70 0.65
0.60
48
600 40
5.06 16.2 15.0 13.08 13.2 12.6 11.4 10.8 10.2 9.0
7.8
7.2
55 140
17.7 1.50 1.40 1.30 1.20 1.20 1.10 1.00 0.94 0.83 0.77 0.72
0.66
80
10.13
0.24
15
30
3.80
0.72
1.90 11.3 10.5 9.70 9.30 8.80 8.00 7.60 7.10 6.30 5.90 5.50
5.0
4.43 2.00 1.90 1.70 1.70 1.70 1.40 1.40 1.30 1.10 1.10 1.00
0.90
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35
Fitting
Description
Pipe Exit
Projecting
Sharp-Edged
Rounded
8.4
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Page 3 of 5
Pipe Entrance
Inward Projecting
0.78
Sharp-Edged
0.50
r/d=0.02
0.28
r/d=0.04
0.24
r/d=0.06
0.15
r/d=0.10
0.09
r/d<0.14
0.04
The K values given below are for making estimates of friction loss in cases not covered in the previous tables.
Type of Fitting
K Value
Disk or Wobble Meter
3.4 - 10
Rotary Meter (Star or Cog-Wheel Piston)
10
Reciprocating Piston Meter
15
Turbine Wheel (Double-Flow) Meter
5 - 7.5
Bends w/Corrugated Inner Radius
1.3 - 1.6 times value for smooth bend
Example: Determine L (friction loss in pipe fittings in terms of equivalent length
in feet of straight pipe).
Assume a 6" angle valve for Schedule 40 pipe size.
Select the appropriate K value for such and select D and f for Schedule 40 pipe
from the table below where K is the pipe diameter in feet.
Pipe Size
Pipe Size
Pipe Size
Pipe Size
D
D
D
D
Inches
f
Inches
f
Inches
f
Inches
f
feet
feet
feet
feet
Sch. 40
Sch. 40
Sch. 40
Sch. 40
0.0518 0.027
2
0.2058 0.018
10
0.8350 0.014
24
1.8857 0.012
0.0687 0.025
3
0.2557 0.018
12
0.9948 0.013
30
2.3333 0.011
1
0.0874 0.023
4
0.3355 0.017
14
1.0937 0.013
36
2.8333 0.011
1
0.1150 0.022
5
0.4206 0.016
16
1.250 0.013
42
3.3333 0.010
1
0.1342 0.021
6
0.5054 0.015
18
1.4063 0.012
48
3.8333 0.010
2
0.1723 0.019
8
0.6651 0.014
20
1.5678 0.012
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6/13/01
Page 4 of 5
.622
.027
.41
.824
.025
.55
1
1.049
.023
.70
1
1.380
.022
.92
1
1.610
.021 1.07
2
2.067
.019 1.38
2
2.469
.018 1.65
3
3.068
.018 2.04
4
4.026
.017 2.68
5
5.047
.016 3.36
6
6.065
.015 4.04
8
7.981
.014 5.32
10
10.02
.014 6.68
12
11.938 .013 7.96
14
13.124 .013 8.75
16
15.00
.013 10.0
18
16.876 .012 16.9
20
18.814 .012 12.5
24
22.628 0.12 15.1
30
28
.011 18.7
36
34
.011 22.7
42
40
.010 26.7
48
46
.010 30.7
L/D
90
elbow
1.55
2.06
2.62
3.45
4.03
5.17
6.17
7.67
10.1
12.6
15.2
20.0
25.1
29.8
32.8
37.5
42.2
47.0
56.6
70
85
100
115
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30
Long
radius
90 or
45 std
elbow
.83
1.10
1.40
1.84
2.15
2.76
3.29
4.09
5.37
6.73
8.09
10.6
13.4
15.9
17.5
20.0
22.5
25.1
30.2
37.3
45.3
53.3
61.3
16
Std
tee
thru
flow
1.04
1.37
1.75
2.30
2.68
3.45
4.12
5.11
6.71
8.41
10.1
13.3
16.7
19.9
21.8
25.0
28.1
31.4
37.7
46.7
56.7
66.7
76.7
20
Std
tee
branch
flow
3.11
4.12
5.25
6.90
8.05
10.3
12.3
15.3
20.1
25.2
30.3
39.9
50.1
59.7
65.6
75.0
84.4
94.1
113
140
170
200
230
60
Close
return
bend
2.59
3.43
4.37
5.75
6.71
8.61
10.3
12.8
16.8
21.0
25.3
33.3
41.8
49.7
54.7
62.5
70.3
78.4
94.3
117
142
167
192
50
Swing
check
valve
full open
5.18
6.86
8.74
11.5
13.4
17.2
20.6
25.5
33.6
42.1
50.5
33.3
41.8
49.7
54.7
Angle
valve
full
open
7.78
10.3
13.1
17.3
20.1
25.8
30.9
38.4
50.3
63.1
75.8
99.8
125
149
164
62.5
70.3
78.4
94.3
188
210
235
283
to 6
= 100
24 to 48
=50
150
Globe
90Welding
valve
Butterelbow
fly valve
full
r/d = r/d =
valve
17.6
23.3
29.7
39.1
45.6
58.6
7.75
3.45 2.07
70.0
9.26
4.12 2.47
86.9
11.5
5.11 3.07
114
15.1
6.71 4.03
143
18.9
8.41 5.05
172
22.7
10.1 6.07
226
29.9
13.3 7.98
284
29.2
16.7 10.0
338
34.8
19.9 11.9
372
38.3
21.8 13.1
25.0 15.0
425
31.3
28.1 16.9
478
35.2
31.4 18.8
533
39.2
37.7 22.6
641
47.1
46.7
28
56.7
34
66.7
40
76.7
46
340
20
12
Mitre bend
45
90
2.58
3.08
3.84
5.03
6.31
7.58
9.98
12.5
14.9
16.4
18.8
21.1
23.5
28.3
35
43
50
58
10.3
12.3
15.3
20.1
25.2
30.3
39.9
50.1
59.7
65.6
75.0
84.4
94.1
113
140
170
200
230
15
60
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