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Open slightly the discharge valve (only if no auxiliary venting pipe is
installed).
Open all valves in suction line.
Switch on the pump
Wait until pump has primed and note this priming time. Then close
the discharge isolating valve and measure max pressure (zero flow).
Compare this pressure to the shutoff pressure available on the hydraulic
curve.
In order to avoid overheating of the liquid inside the pump the
pump should not work more than 20 to 30 seconds against a closed
discharge valve.
If expected pressure is reached then open progressively the discharge
valve.
If there is no liquid delivered or if discharge pressure is too low
then see chapter "trouble shooting".
8.4 RUNNING CHECKS
During operation of pump in duty conditions (capacity, head,
temperature, ...) the following points must be checked :
Check and note pump duty point. If necessary convert pressure value
from bar indicated on the pressure gauge to mwc :
HMT
= (P
x 100) / (SG x 9,806) with SG= fluid Specific Gravity.
mce
bar
Check and note current consumption on each phase of the motor.
Check calibration of motor protections.
Check temperature of ball bearings (on bearing housing surface).
Check flexible coupling alignment after several pump starts (only for
concerned pumps variants).
Check tightening of flanges fastening bolts.
Check there is no leakage and no abnormal running noise.
When pumping hot fluids, the definitive coupling alignment should
be done only when system nominal temperature is reached and
stabilized. See chapter 7.1.4 COUPLING ALIGNMENT
Check the surface temperature on the bearing bracket and on the
pump casing. Check pumped fluid temperature. Alarm and stop
trips settings should be done according those values. Refer to specific
sensors IOM before adjusting those trips.
8.5 SHUTDOWN
Before the pump is stopped close the discharge isolating valve.
Ensure that the pump runs in that condition no more than few
seconds.
When the pump has come to a standstill : close the suction isolating
valve. If the pump is equipped with auxiliary systems such as a quench,
heating system, flushing, external lubrication, etc ... it must be closed at
the last step.
If temperature is likely to drop below freezing point, pump casing
and auxiliary connected systems should be completely drained or
16
otherwise protected. For prolonged shut-downs an adapted rust
protective coating should be applied to the inside and outside of the
pump.
Pumping explosive, toxic or polluting fluids : make sure that all
necessary actions were taken to avoid the creation of a hazard for
people or environment during drainage operations.
Products which are sent back to WILO must be drained and
cleaned. Pumped fluid should be completely removed from the
pump.
8.6 PRIMING TIME
The suction line drains down into the tank between two starts. The flow
does not appear immediately after pump start but only after a few
seconds : it is called priming time.
Piping will be design in order to allow free air extraction without
counter-pressure (discharge back to tank, vent valve, discharge line
to an atmospheric exhaust ...).
Even if the mechanical seal is equipped with a quench behind the
stationary seat, priming time will be limited to 5 minutes. If
discharge pressure doesn't rise after this time, stop the pump and check
piping system.
For an ATEX application, it may happen that the alarm temperature
is reached before pump has primed. Measure liquid temperature
and modify alarm and stop trips settings accordingly.
Theoritically the pump could prime up to 8 meters but lifting
height will be limited to 6 meters to take suction line head losses
into account.
Check that the system available NPSH (NPSH
than the required NPSH (NPSH
lower point.
Theoretical priming times (Nominal Dia of pipe = pump nominal dia) :
Pump size
Pump speed
40
2900
41
2900
45
2900
46
2900
50
2900
51
2900
60
2900
61
2900
63
2900
65
1450
68
2900
80(-2)
2900
80
2900
83
2900
85
1450
88
2900
88 (210)
2900
100
2900
105
1450
105
2300
105 T114
1450
108
2900
120
1450
) is always higher
A
) of pump when fluid level is at its
R
Priming time in seconds vs
suction lift height. [Tt]
2
3
4
5
6
21
47
78
135
27
57
93
153
12
22
35
47
62
5
8
13
23
34
17
29
46
83
19
34
55
87
155
19
29
42
56
77
10
15
21
29
41
7
10
14
19
33
30
58
83
186
9
14
19
26
38
36
49
62
74
95
21
53
95
132
14
20
26
31
39
32
63
100
152
4
7
11
18
26
5
8
11
15
20
19
30
38
45
54
38
69
110
167
9
13
17
21
25
30
62
110
189
10
14
18
22
27
10
18
31
50
95
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