SN121 "Multipath" or "Reactive" Medium Duty Silencer
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If you have any questions relating to this or any of our products, please do not hesitate to contact us.
General
Specification
These silencers are designed on the reactive principle with twin chambers in which the exhaust gases are mixed and smoothed, thus absorbing a high proportion of the acoustic energy without causing excessive back pressure.
Construction
A cylindrical shell manufactured from heavy gauge sheet steel, fully welded. The end plates on 50 - 76mm nominal bore (2"-3") are from heavy steel pressings and for larger sizes these are manufactured from flat plate.
End Connectors
Unless otherwise specified, screwed BSP connectors will be supplied on 50mm - 76mm (2" -3") silencers and flanges to BS10 (Table D) on all larger sizes. Flanges to other standards can be supplied on special quotation.
Side Entry Silencers
If these are required, please specify SN 121(SE) when ordering.
| Nominal Bore (A) | Diameter (B) | Length (C) | (D) | (E) | (F) | Approx. weight (kilos) |
| 50 (2") | 250 (10") | 711 (28") | 63 | 10 | ||
| 64 (2½") | 305 (12") | 813 (32") | 76 | 12 | ||
| 76 (3") | 305 (12") | 914 (36") | 102 | 18 | ||
| 89 (3½") | 356 (14") | 914 (36") | 76 | 127 | 254 | 28 |
| 100 (4") | 356 (14") | 1067 (42") | 76 | 127 | 254 | 32 |
| 125 (5") | 406 (16") | 1245 (49") | 76 | 152 | 279 | 48 |
| 150 (6") | 457 (18") | 1448 (57") | 76 | 165 | 305 | 64 |
| 200 (8") | 559 (22") | 1778 (70") | 76 | 190 | 356 | 95 |
| 250 (10") | 660 (26") | 2134 (84") | 89 | 229 | 419 | 150 |
| 300 (12") | 762 (30") | 2591 (102") | 89 | 254 | 470 | 270 |
| 350 (14") | 914 (36") | 2794 (110") | 89 | 292 | 546 | 450 |
| 400 (16") | 1000 (39") | 3124 (123") | 89 | 318 | 597 | 560 |
| 450 (18") | 1168 (46") | 3480 (137") | 102 | 343 | 686 | 800 |
| 500 (20") | 1270 (50") | 3810 (150") | 102 | 381 | 737 | 1000 |
| 550 (22") | 1372 (54") | 4140 (163") | 152 | 325 | 838 | 1220 |
| 600 (24") | 1473 (58") | 4420 (174") | 152 | 350 | 888 | 1560 |
Note (i) Dimensions in millimetres
(ii) BSP Drain plug fitted at inlet end
(iii) Dimension 'E' is a minimum distance
Typical Noise Attenuation Graph
The above graph is based on simplified theoretical considerations and extrapolated from various noise tests. The actual noise reduction obtained on any particular installation will depend upon the power and type of the noise source, the local environment and the selection of the correct size of silencer for that engine.
Velocity / Resistance Graph
This graph is based on simplified theoretical considerations and is issued as a guide. The actual resistance experienced will depend on a number of factors affecting the individual installation.
If you have any questions relating to this or any of our products, please do not hesitate to contact us.