Flint & Walling Constant Pressure Pumping Stations - end suction centrifugal pumps User Manual
Page 6
6
95 North Oak Street • Kendallville, IN 46755
Copyright 2012. All Rights Reserved.
ROTARY SHAFT SEAL
The mechanical shaft seal should be replaced if water
is noticed around the motor shaft. Remove case and
impeller and, using two screw drivers to pry on each
side, remove seal stationary seat. Clean seat area of
frame, install new stationary seat with ceramic surface
facing out and slide new rotating element over shaft
sleeve with hard carbon surface against ceramic seat.
Be sure to keep all surfaces clean. Lubricating seal
parts with water will help the installation of the seal.
Reinstall impeller and pump case.
CAUTION: Make certain that the power supply is
disconnected before attempting to service the unit!
Failure to do so could result in personal injury or fatal
electrical shock.
MOTOR
Keep motor clean and dry. It is drip-proof when
installed horizontally and the windings are protected
from excess humidity, but extreme conditions should
be avoided when possible. If motor fails to run, be
sure power is on, all switches or electrical controls are
closed, fuses are in order and all electrical connection
are tight. (Motor must be repaired by Authorized
Repair Station under terms of guarantee.)
FAILURE TO PUMP
If the motor runs, but no water is pumped, be sure
pump is primed, that there are no air leaks in suction
piping, that all gate valves are open and all check valves
operate.
NET POSITIVE SUCTION HEAD (NPSH)
NPSH combines all of the factors limiting the suction
side of a pump; internal pump losses, static suction
lift, friction losses, vapor pressure and atmospheric
conditions. It is important to differentiate between
REQUIRED NPSH and AVAILABLE NPSH.
NPSH REQUIRED
REQUIRED NPSH is a factor designed into a pump and
measurable in the test laboratory by the manufacturer.
Testing facilities can determine losses in the suction
piping, static lift and barometric pressures.
NPSH AVAILABLE
1. The term for providing sufficient pressure on the
suction, at the impeller eye, to prevent “boiling” is
known as NPSH AVAILABLE. It is a function of the
pumping system and consists of pressure on the
liquid at its source, the elevation of the liquid with
respect to the impeller center line, losses in the
suction piping and vapor pressure of the liquid.
PROPERTIES OF WATER
Temperature
ºF
Absolute Vapor
Pressure
Specific
Gravity
PSI
Ft. Water
60
0.26
0.59
0.999
85
0.60
1.4
0.996
100
0.95
2.2
0.993
120
1.69
3.9
0.989
130
2.22
5.0
0.986
140
2.89
6.8
0.983
150
3.72
8.8
0.981
160
4.74
11.2
0.977
170
5.99
14.2
0.974
180
7.51
17.8
0.970
185
8.38
20.0
0.969
190
9.34
22.3
0.966
195
10.38
24.9
0.964
200
11.53
27.6
0.963
202
12.01
28.8
0.962
204
12.51
30.0
0.961
206
13.03
31.2
0.960
208
13.57
32.6
0.960
210
14.12
33.9
0.959
212
14.70
35.4
0.958
214
15.29
37.0
0.957
216
15.90
38.4
0.956
218
16.54
40.0
0.956
220
17.19
41.6
0.955
222
17.86
43.3
0.954
224
18.56
45.0
0.953
226
19.28
46.8
0.953
228
20.02
48.6
0.952
230
20.78
50.5
0.951
240
24.97
61.0
0.947
250
29.83
73.2
0.943
300
67.00
168.6
0.918
350
134.60
349.0
0.891
Altitude
(Feet)
Barometer
Inches
Mercury
Atmospheric
Pressure
Boiling
Point ºF
PSIA
(ft. water)
-1000
31.0
15.2
32.5
213.8
-500
30.5
15.0
34.6
212.9
0.0
29.9
14.7
33.9
212.0
+500
29.4
14.4
33.3
211.1
+1000
28.9
14.2
32.8
210.2
+1500
28.3
13.9
32.1
209.3
+2000
27.8
13.7
31.5
208.4
+2500
27.3
13.4
31.0
207.4
+3000
26.8
13.2
30.4
206.5
+3500
26.3
12.9
29.8
205.6
+4000
25.8
12.7
29.2
204.7
+4500
25.4
12.4
28.8
203.8
+5000
24.9
12.2
28.2
202.9
+5500
24.4
12.0
27.6
201.9
+6000
24.0
11.8
27.2
201.0
+6500
23.5
11.5
26.7
200.1
+7000
23.1
11.3
26.2
199.2
+7500
22.7
11.1
25.7
198.3
+8000
22.2
10.9
25.2
197.4
+8500
21.8
10.7
24.7
169.5
+9000
21.4
10.5
24.3
165.5
+9500
21.0
10.3
23.8
194.6
+10000
20.6
10.1
23.4
193.7
+15000
16.9
8.3
19.2
184.0