NAP ACOUSTICS SOUTH EAST ASIA PTE LTD
DESIGNERS & MANUFACTURERS OF NOISE AND VIBRATION CONTROL PRODUCTS

NAP Circular Silencers

Introduction

NAP Circular Silencers are used wherever it is necessary to control the passage of noise along an airpath. They control the noise of ventilating and air-conditioning systems in office buildings, lecture and conference rooms, hotels, hospitals, radio and television studios, and wherever air-conditioning and ventilation systems are installed.

In industrial applications, specially designed and constructed circular silencers control noise from fans and blowers, cooling towers, dust extraction systems and similar air or gas handling equipment such as compressors and turbines.

Construction
NAP Circular Silencers are available in a wide range of sizes from 305mm diameter upwards, and are normally supplied with flanged ends for direct attachment to axial flow fans, or direct to ductwork.

NAP Circular Silencers consist of a galvanised sheetmetal case, fabricated from a minimum of 1.0mm galvanised steel. The inner pod and outside lining are manufactured from high density acoustic infill protected by perforated galvanised steel. The silencers are supplied in a natural galvanised finish on the case, with the weld affected areas being protected with cold galvanising paint. The angle frames are also protected by a corrosion-resistant paint finish.

Model range

A standard range comprising types CS (without pod) and CSP (with central pod) is offered from Ø305mm to Ø2415mm. Each range is available in two lengths. For CS-1D and CSP-1D, the length of silencer is equal to one diameter. The lengths of CS-2D and CSP-2D silencers are equal to two diameters. 1D and 2D are standard lengths, but non-standard lengths are available on request, or to meet special performance requirements. The model prefix is the flange connection diameter of the silencer.

Pressure drop

The pressure drop graph applies to the types CSP-1D and CSP-2D.
Type CS (without concentric pod) has a negligible pressure drop. It is equal to the equivalent length of straight duct plus a roughness factor of 60% for duct velocities up to 15m/s.

Contact NAP Acoustics for acoustic performance data and technical assistance.
Copyright © 1999 NAP Acoustics South East Asia Pte Ltd. All rights reserved.
Information in this document is subject to change without notice