Specifications

®
Exhaust Gas Velocity in Thousands (Ft/Min)
Typical Attenuation Curve dB(A)*
(ACTUAL ATTENUATION MAY VARY ACCORDING TO APPLICATION)
24
22
20
18
16
14
12
10
8
6
4
2
0 12 3 45678 91011 121314
Pressure Drop (Inches of Water)*
Construction Features:
Double wrapped body is standard on all "300" Level
Critical Silencers.
Critical “300” Level Exhaust Silencers
40
35
30
25
20
15
10
5
Typical Attenuation dB (A)*
Octave Band Center Frequency (Hz)
31.5 63 125 250 500 1K 2K 4K 8K
Application:
These silencers are recommended where ambient noise
is low and a high degree of silencing is necessary.
Construction:
Aluminized Steel: Nelson Silencers through
26" O.D. are fabricated of aluminized steel as standard
materials. This material has a maximum operating
temperature of 1250°F.
Mild Steel/Aluminized Steel: Nelson Silencers
30" O.D. and larger are fabricated of mild steel and
aluminized steel. All silencers 30" O.D. and larger have
aluminized steel bodies with all other components
fabricated from mild steel.
Silicone Aluminum Paint: Nelson Silencers through
26" O.D. are given a coat of high heat resistant silicone
aluminum paint.
Primer/Silicone Aluminum Paint: Nelson Silencers
30" O.D. and larger are given a coat of high heat, rust
inhibiting primer and then a topcoat of high heat
resistant silicone aluminum paint. Physical properties
are maintained up to 900°F* on aluminized steel and
1100°F* on mild steel.
“F” Mounting Flange:
Standard in sizes 4" to 22". Drilling
matches 125/150# ASA standard.
Companion flanges available for 4" to 22".
Note: When figuring pressure drop for side inlet or
middle side inlet add 3" H
2
O to back pressure shown
on above curve.
*Estimated
Sample Specification:
The silencer is to be a Nelson Critical "300" Level Silencer constructed of aluminized steel (26" body diameter and
smaller) or mild steel/aluminized steel (larger than 26" body diameter) with all welded construction and suitable for
mounting in any position.
“P” Male Pipe Threads:
NPT ends offered in sizes 3/4"
through 4".
*Estimated
Pressure Drop
QTY - 2