Specific machine performance, Sound level (see 1.9, noise level), 8 specific machine performance – Flowserve LNN User Manual
Page 9: 9 noise level
LNN, LNNV, LNNC USER INSTRUCTIONS ENGLISH 71569074 06-14
Page 9 of 56
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1.8 Specific machine performance
For performance parameters see section 1.5, Duty
conditions. When the contract requirement specifies
these to be incorporated into User Instructions these
are included here. Where
performance data has been
supplied separately to the purchaser these should be
obtained and retained with these User Instructions if
required.
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 1 pW) then
add 17 dBA to the sound pressure value.
Motor size
and speed
kW (hp)
Typical sound pressure level L
pA
at 1 m reference 20 μPa, dBA
3 550 r/min
2 900 r/min
1 750 r/min
1 450 r/min
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)
85
87
83
85
300 (400)
–
87
90
85
86
500 (670)
88
86
1 000 (1 300)
90
88
1 500 (2 000)
90
90
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.