Flowserve LPNV Worthington - Manual (Page 8)

LPNV USER INSTRUCTIONS ENGLISH 87900031 – 06/14
Page 8 of 48
1.9 Noise level
When pump noise level exceeds 85 dBA attention
must be given to prevailing Health and Safety
Legislation, to limit the exposure of plant operating
personnel to the noise. The usual approach is to
control 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 machines above a
certain power level will exceed 85 dBA. In such
situations consideration must be given to the fitting
of an acoustic enclosure to meet local regulations.
Pump noise level is dependent on a number of
factors - the type of motor fitted, the operating
conditions, pipework design and acoustic
characteristics of the building. The levels specified
in the table 1.1 are estimated and not guaranteed. The dBA values are based on the noisiest
ungeared electric motors that are likely to be
encountered. They are Sound Pressure levels at 1
m (3.3 ft) from the directly driven pump, for "free
field over a reflecting plane".
If a pump unit only has been purchased, for fitting
with your own driver, then the "pump only" noise
levels should be combined with the level for the
driver obtained from the supplier. If the motor is
driven by an inverter, it may show an increase in
noise level at some speeds. Consult a Noise
Specialist for the combined calculation.

For units driven by equipment other than
electric motors or units contained within
enclosures, see the accompanying information
sheets and manuals.
Typical sound pressure level, dBA, L
pA
at 1 m reference 20 μPa (L
wA
sound power1 pW where L
pA
>85 dBA)
Motor size
and speed
kW (hp)
1750 rpm 1450 rpm
Pump
only
dBA
Pump &
motor
dBA
Pump
only
dBA
Pump &
motor
dBA
30 (40) 73 73 71 73
37 (50) 73 73 71 73
45 (60) 76 76 74 76
55 (75) 76 76 74 76
75
(100) 77 77 75 77
90 (120) 77 78 75 78
110 (150) 79 80 77 80
132 (175) 79 80 77 80
150 (200) 79 80 77 80
160 (215) 83 84 81 83
200 (270) 85 87 83 85
300 (400) 87 90 85 86
315 (422) 87 90 85 86
355 (475) 87 90 86 87
500 (670) 88 (1) 86 (1)
1000 (1300) 90 (1) 88 (1)
1500 (2000) 90 (1) 90 (1)
(1) Noise levels of machines in this range should be based on actual equipment selected
For 1180 and 960 r/min reduce the 1450 r/min values by 2dBA
For 880 and 720 r/min reduce the 1450 r/min values by 3dBA