18
1
Clearance gap
2
Discharge nozzle
3
Casing cover
4
Drive shaft
5
Bearing bracket
6
Suction nozzle
7
Impeller
8
Shaft seal
9
Rolling element bearing, pump end
10 Rolling element bearing, motor end
The pump is designed with an axial fluid inlet and a radial or tangential outlet. The hydraulic
system runs in its own bearings and is connected to the motor by a shaft coupling.
The fluid enters the pump axially via the suction nozzle (6) and is accelerated outward in a
cylindrical flow by the rotating impeller (7). In the flow passage of the pump casing the kinetic
energy of the fluid is converted into pressure energy. The fluid is pumped to the discharge
nozzle (2), where it leaves the pump. The clearance gap (1) prevents any fluid from flowing
back from the casing into the inlet. At the rear side of the impeller, the shaft (4) enters the
casing via the casing cover (3). The shaft passage through the cover is sealed towards the
atmosphere by a shaft seal (8). The shaft runs in rolling element bearings (9 and 10), which are
supported by a bearing bracket (5) linked with the pump casing and/or casing cover.
The pump is sealed by a shaft seal.
Standardised mechanical seal or stuffing box packing
4.6 Noise characteristics
Table 10: Surface sound pressure level LpA3)4)
Design
Function
Sealing
Rated
power
input
P
N
[kW ]
Pump
Pump set
2900 rpm
[dB]
1450 rpm
[dB]
960 rpm
760 rpm
[dB]
2900 rpm
[dB]
1450 rpm
[dB]
960 rpm
760 rpm
[dB]
1
54
53
52
63
58
56
2
56
55
53
66
60
58
3
57
56
55
68
62
60
4
59
58
56
69
63
61
6
61
59
58
71
65
62
8
62
61
59
72
66
64
11
64
63
61
74
68
65
15
66
65
63
75
69
67
19
67
66
64
76
70
68
22
68
67
65
77
71
68
30
70
68
66
78
72
70
37
71
70
67
79
73
70
45
72
71
68
80
74
71
55
73
72
69
80
74
72
75
75
73
71
81
76
73
90
76
74
71
82
76
73
110
77
75
72
82
77
74
132
78
76
73
83
77
75
160
79
77
74
84
78
75
200
80
78
75
84
79
76
250
81
79
-
85
80
-
3) Spatial average; as per ISO 3744 and EN 12639; valid for operating range Q/Qopt = 0.8 - 1.1 and non-cavitating pump
operation. If noise levels are to be guaranteed: Add + 3 dB for measuring and constructional tolerance.
4) Increase for 60 Hz operation: 3500 rpm+ 3 dB; 1750 rpm + 1 dB; 1160 rpm:± 0 dB
4 Description of the Pump (Set)
