In simple terms, silencing is the act of reducing noise to
an acceptable level for the location or working conditions
surrounding the noise producing equipment. MAXIM’s money
saving line of stock silencers readily solves noise problems
of many applications. Comparison of the typical attenuation
curves for individual silencer models will show the relative
capabilities of different designs.
CHAMBER
TYPE SILENCERS
MODELS M21, M31, M41, M51 AND MUL
Chamber type silencers provide the best noise control across
the entire audible range. The basic design incorporates
non-resonant side tube arrangements to permit passage of the
exhaust gases from one chamber to another. This creates a
reversal of flow and develops a predictable amount of back
pressure. Another important feature of chamber type silencers is
the availability of side inlet exhaust connections. Units of
this type, except for spark arrestor designs, can also be
supplied with side outlet exhaust connections. These side
connections, while having little effect on the pressure drop,
will in many instances, greatly facilitate installation of the
silencer by eliminating the need for elbows in the piping.
SILENCER MODEL |
M21 |
Good chamber type silencer. Use in areas where
background noise is relatively high and constant and the
need for higher degree of silencing is minimal. Expected
attenuation is 17 to 20 dBA. |
M31 |
Better chamber type silencer for
residential areas where background noise is present but
not objectionable. With expected attenuation of 20 to 24
dBA, the M31 is intended to bring most exhaust noise
levels down to match the ambient noise levels. |
M41 |
Excellent chamber type silencer. Use an M41 in quiet
residential area where background noise is relatively
low and critical grade silencing is desired. Expected
attenuation is 24 to 28 dBA. |
M51 |
Best chamber type silencer for
"Hospital Grade" silencing. Use an M51 for the highest
degree of silencing for areas requiring the maximum
noise reduction available from standard chambered
silencer design. Expected attenuation is 28 to 32 dBA. |
MUL |
The MUL is comparable to the M31 for pipe thread
sizes 1" to 31/2". |
COMPACT CHAMBER
TYPE SILENCERS
MODELS MD26, MD36
Compact design is engineered to provide a “critical”
grade of attenuation while minimizing space usage. Excellent
application for packaged power and process skids where space
is a
premium. Dual inlets and other custom designs can be easily
incorporated. Low Temperature design not only reduces
skin temperature, but radiated noise as well. Heavy
duty, welded construction with temperature resistant
insulation within a double wall construction. The inlet and
outlets are standard with ANSI drilled 125/150 lb flanges.
Standard finish is high temperature resistant silicone
black. Alternate finishes may be available upon request.
Standard material is carbon steel. Stainless steel is
optional.
SILENCER MODEL |
MD26 |
Expected attenuation is 28-32 dBA |
MD36 |
Expected attenuation
is 33-37 dBA |
CHAMBER TYPE SPARK
ARRESTOR SILENCERS
MODELS MSA1, MSA2, MSA3 AND MSA4
Spark arrestor silencers have application in marine service,
refineries and other hazardous environments. These are chamber
type designs. The
retention of hot carbon and soot particles minimizes danger and
helps to provide a cleaner area and atmosphere.
SILENCER MODEL |
MSA1 |
Highly efficient spark arrestor silencer with M21
attenuation characteristics. Expected attenuation is 17
to 20 dBA. |
MSA2 |
Highly efficient spark arrestor
silencer with M31 attenuation characteristics. Expected
attenuation is 20 to 24 dBA. |
MSA3 |
Highly efficient spark arrestor silencer with M41
attenuation characteristics. Expected attenuation is 24
to 28 dBA. |
MSA4 |
Highly efficient spark arrestor
silencer with M51 attenuation characteristics. Expected
attenuation is 28 to 32 dBA. |
LOW PRESSURE DROP,
STRAIGHT THROUGH SILENCERS
MODELS MT21, MT31 AND MT41
Straight through silencers have an unobstructed passage
through the silencer with no reversal of flow. The result is a
pressure drop across the silencer only slightly above that
caused by an equivalent length of pipe. Side connections are not
practical in this design due to increase in pressure drop and
price. Since noise attenuation provided by straight through
design is less than that provided by chamber design silencers
incorporating a reversal of flow, the MT series is best used in
applications where low pressure drop is the primary
consideration.
SILENCER MODEL |
MT21 |
For noise control applications
requiring low pressure drop. Expected attenuation is 13
to 16 dBA. |
MT31 |
For average attenuation of
objectionable noise where effective though not complete
silencing is required with low pressure drop. Expected
attenuation is 16 to 19 dBA. |
MT41 |
For better than average noise
attenuation with low pressure drop requirements.
Expected attenuation is 19 to 22 dBA. |
MARINE ENGINE WET
EXHAUST SILENCERS
MODELS MP-11, MP-31 AND MP-41
Constructed of stainless steel, the MAXIM MP series silencers are
available for wet marine engine exhaust applications. Water is
injected upstream of the silencer in sufficient quantity to
reduce the exhaust temperature to a maximum of 200o F. The MP-11
may be installed in series with an MP-31 or MP-41 to provide
additional attenuation.
SILENCER MODEL |
MP-11 |
Low pressure drop with good performance. Expected
attenuation is 15 to 18 dBA. |
MP-31 |
Medium pressure drop with better performance.
Expected attenuation is 20 to 25 dBA. |
MP-41 |
Highest performance for a wet exhaust application.
Expected attenuation is 30 to 35 dBA. |
VENT SILENCERS FOR
COMPRESSED AIR, GAS AND STEAM
MODELS VT-S, VT-1, VT-2 AND VT-3
The MAXIM VT series silencers are designed to attenuate high
frequency noise associated with venting of high pressure air,
gas or steam to atmosphere. These ruggedly designed silencers
feature all welded construction with concentric acoustically
packed panels.
SILENCER MODEL |
VT-1 |
Good vent silencer for controlling noise generated
by pressurized gases released to atmospheric pressure.
Expected attenuation is 35 to 40 dBA. |
VT-2 |
Better vent silencer for controlling noise generated
by pressurized gases released to atmospheric pressure.
Expected attenuation is 42 to 45 dBA. |
VT-3 |
Best vent silencer for controlling noise generated
by pressurized
gases released to atmospheric pressure. Expected
attenuation is 50 to 55 dBA. |
ABSORPTIVE DESIGN
INTAKE MODELS: FP, FPC, FPS
DISCHARGE MODELS: FPE, FPCE, FPSE
Intake models are built "cleaned for intake service." The FPE
model in stock sizes 4" through 12" is also built clean for
intake use and may be substituted for the FP. The "E"
designation on any FP design indicates that the silencer is
built to withstand hot engine exhaust service.
Absorptive silencer designs are compact and have low pressure
drops. They are ideal for many applications for fan intakes and
discharges, engine air intakes, small steam vents and
centrifugal compressor inlets where absorption of high frequency
noise is important. An FPE, FPCE, FPSE installed in series with
an M-line chamber type silencer, can provide 10-20 enhancement
of the overall dBA silenced exhaust noise of a reciprocating
engine. Addition of an absorptive design silencer may improve
the overall attenuation of the system by 10 to 20 dBA.
SILENCER MODEL |
FP / FPE |
Straight through, absorptive silencer design with no
center panel for low pressure drop service. Expected
attenuation is 20 dBA. |
FPC / FPCE |
Similar to the FPE but with an internal center panel
which displaces part of the nominal flow area. Pressure
drop is higher but the FPC is more compact in diameter,
length and weight. Available in sizes 14" and up, the
FPC is excellent for engine and compressor intakes and
fan intakes and discharges. Expected attenuation is 20
to 25 dBA. |
FPS / FPSE |
Designed with a center panel, the FPS / FPSE body
diameter is enlarged to enable an annular flow passage
equal to the full nominal flow area. Pressure drop is
intermediate between the FP and FPC models. Expected
attenuation is 15 to 30 dBA. |
PRESSURIZED
SERVICE, ASME CODE DESIGN
MODELS ILL AND ILM
Designed to ASME Code, MAXIM offers the models ILL and ILM to
reduce the noise generated by valves and compressors. Typical
noise reductions associated with high pressure applications is
within the range of 15 dBA to 30 dBA.
BLOWER
SILENCERS
MAXIM MODEL MB11, MB21 AND MB31
Highly efficient in acoustic design, the MB series is used to
reduce the noise radiating from blower piping or blower opening.
Typical applications are for rotary positive blower intake and
discharge, vacuum pump intake and discharge, and centrifugal
blower intake and discharge.
SILENCER MODEL |
MB11 |
With its straight through acoustically packed design
the MB11 offers good silencing for many blower
applications. Typical attenuation is 15 to 30 dBA. |
MB21 |
An efficient economical design, the MB21 is useful
for blower noise reduction in applications where some
background noise is always present and high degree
silencing is not required. Typical attenuation is about
24 dBA. |
MB31 |
A superior design, the MB31 incorporates an
acoustically packed connection with a chamber type
design to offer a high degree of attenuation of blower
intake or discharge noise. Typical attenuation is about
30 dBA. |
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