DMX/DMXD/DMXH/DMXDH USER INSTRUCTIONS ENGLISH 71569282 - 10/09
Page 8 of 60
Oil lubricated units only:
1.8 Specific machine performance
For performance parameters see 10.4
Customer
Data Sheet.
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.
1.9.1
Pump noise levels
The following tables may be used to determine the
estimated sound pressure levels (SPL), expressed in
dBA (dB), for DMX/DMXD/DMXH/DMXDH pumps.
The values shown have been derived from actual
noise test data and are based on the following
conditions:
a) Equipment is located in a free field above a
reflecting plane in which the reduction in noise
level in all directions is 6 dB in each octave band
for each doubling of distance.
b) Background noise is 10 dB (minimum) below all
noise levels in each octave band.
c) The values shown are at a distance of 1 m
(3.281 ft), horizontally from major pump surfaces
and 1.5 m (4.78 ft) above the floor using the
standard pressure reference of 20 µPa
(0.00002 N/m
2
).
d) Overall noise level, dBA ("A" scale) is determined
at points of maximum noise level, and the values
of all mid-band frequencies are basis "C" scale
readings.
1.9.2
Overall noise level
Tables below show dBA levels for two stage and
three or more stage pumps, based on the best
efficiency point BEP at design RPM and required
impeller diameter.
For specific gravities less than 1.0, use 1.0 specific
gravity. For specific gravities above 1.0, use the
actual specific gravity.
When the required condition flow falls outside the
range of 75% to 125% of BEP, a Part Load
Correction (PLC) must be added to the noise levels
as follows:
Percent of BEP at required Impeller
Diameter
PLC DB
74 to 62 % or 126 to 136 %
+1
61 to 50 % or 137 to 150 %
+2
49 to 38 %
+3
37 to 25 %
+4
Brake Horse Power at Best Efficiency
Point.
dBA
2 Stage pump
250 to 350
87
350 to 500
88
500 to 700
89
700 to 940
90
940 to 1100
91
1100 to 1300
92
1300 to 1500
93
Above 1500, contact Flowserve
94
