Solar System Design Guide
6020 457 - 01
76
Recommended Operating Range
*It is recommended that you add a safety factor of 10% to 20 % to the values in the table
Fluid Velocity and Pressure Drop (Steel)
Pressure Drop and Fluid Velocity for Steel (Sch.40)
1/2” Steel (Sch.40)
3/4” Steel (Sch.40)
1” Steel (Sch.40)
Flow
Rate
Pressure
Drop
Fluid
Velocity
Pressure
Drop
Fluid
Velocity
Pressure
Drop
Fluid
Velocity
USG/min
(L/h)
(L/min)
ft/hd per 100 ft
mbar/m
ft/s
m/s
ft/hd per 100 ft
mbar/m
ft/s
m/s
ft/hd per 100 ft
mbar/m
ft/s
m/s
0.55
125
2.1
0.54
0.53
0.58
0.18
0.66
150
2.5
0.74
0.73
0.70
0.21
0.77
175
2.9
0.97
0.95
0.81
0.25
0.88
200
3.3
1.23
1.20
0.93
0.28
1.10
250
4.2
1.81
1.78
1.16
0.35
1.32
300
5.0
2.49
2.44
1.39
0.43
0.72
0.70
0.79
0.24
1.54
350
5.8
3.26
3.20
1.63
0.50
0.94
0.92
0.93
0.28
1.76
400
6.7
4.12
4.04
1.86
0.57
1.19
1.16
1.06
0.32
1.98
450
7.5
5.07
4.97
2.09
0.64
1.46
1.43
1.19
0.36
0.47
0.47
0.74
0.22
2.20
500
8.3
6.09
5.97
2.32
0.71
1.75
1.72
1.32
0.40
0.57
0.56
0.82
0.25
2.64
600
10.0
8.38
8.22
2.79
0.85
2.41
2.36
1.59
0.48
0.79
0.77
0.98
0.30
3.08
700
11.7
10.97
10.76
3.25
0.99
3.16
3.09
1.85
0.57
1.03
1.01
1.14
0.35
3.52
800
13.3
13.86
13.60
3.72
1.13
3.99
3.91
2.12
0.65
1.30
1.27
1.31
0.40
3.96
900
15.0
17.04
16.71
4.18
1.28
4.90
4.80
2.38
0.73
1.60
1.57
1.47
0.45
4.40
1000
16.7
20.49
20.09
4.65
1.42
5.89
5.78
2.65
0.81
1.92
1.88
1.63
0.50
6.61
1500
25.0
11.98
11.74
3.97
1.21
3.90
3.83
2.45
0.75
8.81
2000
33.3
19.81
19.43
5.30
1.62
6.46
6.34
3.27
1.00
11.01
2500
41.7
9.55
9.36
4.09
1.25
13.21
3000
50.0
13.13
12.88
4.90
1.50
Equivalent Length of Pipe for Valves & Fittings
Nominal
Pipe Size
90º
Elbow
Standard
Radius
90º
Elbow
Long
Radius
45º
Elbow
Standard
Radius
Tee -
Side
Port
Flow
Tee -
Straight
Through
Flow
Gate
Valve -
Open
Globe
Valve -
Open
90º
Angle
Valve
Swing
Check
Valve
1/2”
1.6
1.0
0.8
3
1.6
0.7
17
7
6
3/4”
2.0
1.4
0.9
4
2.0
0.9
22
9
8
1”
2.6
1.7
1.3
5
2.6
1.0
27
12
10
1-1/4”
3.3
2.3
1.7
7
3.3
1.5
36
15
14
1-1/2”
4.3
2.7
2.2
9
4.3
1.8
43
18
16
Pressure Drop for Commonly Used Valves & Fittings
Design and Operation