9 noise level – Flowserve LN User Manual
Page 9
LN, LNE, LNH, LNV, LNEV, LNC and LNEC USER INSTRUCTIONS ENGLISH 71576423 11-09
Page 9 of 32
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1.9 Noise level
Attention must be given to the exposure of personnel
to the noise, and local legislation will define when
guidance to personnel on noise limitation is required,
and when noise exposure reduction is mandatory.
This is typically 80 to 85 dBA.
The usual approach is to control the exposure time to
the noise or to enclose the machine to reduce emitted
sound. You may have already specified a limiting
noise level when the equipment was ordered,
however if no noise requirements were defined, then
attention is drawn to the following table to give an
indication of equipment noise level so that you can
take the appropriate action in your plant.
Pump noise level is dependent on a number of
operational factors, flow rate, pipework design and
acoustic characteristics of the building, and so the
values given are subject to a 3 dBA tolerance and
cannot be guaranteed.
Similarly the motor noise assumed in the “pump and
motor” noise is that typically expected from standard
and high efficiency motors when on load directly
driving the pump. Note that a motor driven by an
inverter may show an increased noise at some
speeds.
If a pump unit only has been purchased for fitting with
your own driver then the “pump only” noise levels in the
table should be combined with the level for the driver
obtained from the supplier. Consult Flowserve or a
noise specialist if assistance is required in combining
the values.
It is recommended that where exposure approaches
the prescribed limit, then site noise measurements
should be made.
The values are in sound pressure level L
pA
at 1 m
(3.3 ft) from the machine, for “free field conditions
over a reflecting plane”.
For estimating sound power level L
WA
(re 1pW) then
add 17 dBA to the sound pressure value.
Typical sound pressure level L
pA
at 1 m reference 20
µ
Pa, dBA
3 550 r/min
2 900 r/min
1 750 r/min
1 450 r/min
Motor size
and speed
kW (hp)
Pump
only
Pump and
motor
Pump
only
Pump and
motor
Pump
only
Pump and
motor
Pump
only
Pump and
motor
5.5 (7.5)
76
77
72
75
66
67
64
65
7.5 (10)
76
77
72
75
66
67
64
65
11(15)
80
81
76
78
70
71
68
69
15 (20)
80
81
76
78
70
71
68
69
18.5 (25)
81
81
77
78
71
71
69
71
22 (30)
81
81
77
79
71
71
69
71
30 (40)
83
83
79
81
73
73
71
73
37 (50)
83
83
79
81
73
73
71
73
45 (60)
86
86
82
84
76
76
74
76
55 (75)
86
86
82
84
76
76
74
76
75 (100)
87
87
83
85
77
77
75
77
90 (120)
87
88
83
85
77
78
75
78
110 (150)
89
90
85
87
79
80
77
80
150 (200)
89
90
85
87
79
80
77
80
200 (270)
1
1
1
1
85
87
83
85
300 (400)
87
90
85
86
500 (670)
88
1
86
1
1 000 (1 300)
90
1
88
1
1 500 (2 000)
–
90
1
90
1
1
The noise level of machines in this range will most likely be of values which require noise exposure control, but typical values are inappropriate.
Note: for 1 180 and 960 r/min reduce 1 450 r/min values by 2 dBA. For 880 and 720 r/min reduce 1 450 r/min values by 3 dBA.