Table 2 - FRICTION LOSS FOR PLASTIC PIPE*
Loss of head in feet due to friction per 100 feet of pipe
Nominal
Pipe Size
U.S. GPM
3/4"
4
3.75
5
5.66
6
7.95
7
10.60
8
13.50
9
16.80
10
20.40
11
24.40
12
28.60
14
38.00
16
48.60
18
60.50
20
73.50
TROUBLESHOOTING
Problem
Pump not properly primed.
Speed too low.
Failure to pump
Total head more than for which pump was intended. A pump designed for higher head needed.
Suction lift is too great.
Air pockets or leaks in suction line.
Clogged impeller.
Strainer too small or clogged.
Reduced capacity
Insufficient submergence of suction line.
and/or head
Excessive suction lift.
Total head more than that for which
the pump was intended.
Excessively worn impeller.
Air leaks in suction line.
Excessive lift and operating too near shut-off point.
Pump loses prime
Water level drops while pumping,
uncovering suction piping.
Bent shaft and/or damaged bearings.
Mechanical
Suction and/or discharge piping not properly
troubles and noise
supported and anchored.
1"
1-1/4''
1-1/2''
1.15
0.30
0.14
1.75
0.46
0.22
2.45
0.65
0.31
3.25
0.86
0.41
4.16
1.10
0.52
5.17
1.35
0.65
6.31
1.67
0.79
7.58
1.98
0.95
8.85
2.33
1.10
11.80
3.10
1.46
15.10
3.96
1.87
18.70
4.93
2.33
22.80
6.00
2.83
Possible Cause
Loss of head in meters due to friction per 100 meters of pipe
Nominal
Pipe Size
L/Min.
20 mm
2''
15
–
20
–
25
–
30
–
35
–
40
–
45
0.23
50
0.27
55
0.32
60
0.43
65
0.55
70
0.69
75
0.84
Make sure pump casing and suction line are full of water. See priming instructions.
s
WARNING
!
connections and system grounding must comply with the National Electrical Code (NEC)
and with any local codes and ordinances. Employ a licensed electrician. Check voltage at
motor terminals and at meter when pump is operating. If low, refer to wiring instructions
or check with your power company. Check loose connections.
Locate pump closer to source of water. Make sure suction piping is large enough.
Check suction piping.
Remove and clean.
Use larger strainer or clean.
Add lengths of suction pipe to keep submerged end well below the water surface.
If caused by suction pipe friction, enlarge piping.
A pump designed for higher head is needed.
Order replacement parts using Replacement Parts list.
Check suction piping.
Move pump nearer water level.
Check water supply. Add length of pipe to suction to keep submerged end under water.
Take motor to authorized motor repair shop.
See that all piping is supported to relieve strain on pump assembly.
8
25 mm
32 mm
3.7
1.15
0.30
5.3
1.64
0.43
7.1
2.18
0.56
13.5
4.13
1.08
16.3
5.00
1.31
23.5
7.30
1.90
28.3
8.74
2.31
34.2
10.60
2.79
40.7
12.60
3.32
48.1
14.90
3.92
55.7
17.30
4.45
63.8
19.70
5.20
72.2
22.40
5.89
*For galvanized pipe, double the figures.
Remedy
ELECTRICAL PRECAUTIONS. All wiring, electrical
40 mm
50 mm
0.13
–
0.19
–
0.27
–
0.49
–
0.61
–
0.88
0.25
1.07
0.29
1.32
0.38
1.56
0.46
1.85
0.54
2.15
0.63
2.46
0.73
2.78
0.83