Attenuators Rectangle / Bend / Circular

Type R / A & B / C

The well established range of TEK rectangular attenuators is designed to give the building services industry a practical product for all situations. They have all been researched and designed by a leading independent acoustic consultant and tested to BS 4718 1971.

All TEK products are designed in-house by engineers with many years’ experience. This means that we are not restricted to standard sizes and attenuators can be tailor-made to meet your requirements. Our acoustic design service is available to ensure that you receive the best possible advice at the planning stage, thereby avoiding site problems later on.

Rectangular Attenuator

Casing & Splitters:

  • The outer casing is constructed from pre-galvanised steel sheet having a minimum thickness of 1.0mm up to a maximum width and height of 1200mm and a minimum thickness of 1.2mm over 1200mm.
  • Pittsburgh longitudinal joints are used as standard, all in accordance with current HVCA specification.
  • Splitters comprise an acoustic infill. retained behind perforated or expanded galvanised steel sheet, having a minimum thickness of 0.7mm. The splitters are contained within galvanised 1.0mm sheet steel channels.
  • Inlet fairings are riveted to the front of each splitter to lower the pressure drop across the attenuators. The splitters are fixed to the attenuator casing with sealed rivets. Half width splitters are fixed to each side wall of the casing to provide sidelinings.
  1. Rolled angle steel red leaded flanges which are fixed to the casing with sealed rivets. Casings are returned 12mm over end flanges.
  2. Slide-on flange connections as detailed in HVCA specification DW142, figure 41, suitable for low or high velocity systems. Gaskets, cleats and matching flanges normally supplied by others.
  3. Plain spigot ends.

The notation for a standard rectangular attenuator is type RCP. The prefix R and suffix P are as indicated below. the second letter C indicates a standard splitter.

Prefix R: Standard rectangular attenuators.
Prefix S: Splitters only.

Prefix A: Bend attenuators are available, supplied with short cord turning vanes installed in the airways (having horizontal splitters).
Prefix B: As Prefix A with vertical splitters.
Suffix P: Splitter acoustic infill retained behind perforated sheet steel.
Suffix L: Attenuators may be supplied with low loss fairing on the splitter end to lower pressure drop across the attenuator. Acoustic performance of the attenuator will be degraded.

Circular Attenuator

Casing & Splitters:

  • The outer casing is constructed from pre-galvanised steel sheet having a minimum thickness of 1.0mm up to a maximum diameter of 1200mm and a minimum thickness of 1.2mm over 1200mm.
  • Pittsburgh longitudinal joints are used as standard, all in accordance with current HVCA specification.
  • The casing is lined with acoustic infill, faced with glass fibre tissue, retained behind perforated or expanded galvanised steel not less than 0.7mm thick.
  • Where required circular pods can be fitted, comprising acoustic infill retained behind perforated, or expanded galvanised steel having a minimum thickness of 0.7mm.
  • The pods have a cone inlet and flat end on outlet.
  1. Threaded inserts to match flange drillings of all makes of axial flow fans or specific customer requirements.
  2. Plain spigot ends.

Prefix C: Standard circular attenuator.
Prefix P: Pod installed in circular attenuator.
Prefix D: This is preceded by a number (normally 1 or 2) indicating the length of a circular attenuator as a multiple of the attenuator internal diameter.

General Specifications

The infill is inorganic mineral wool or glass fibre rigid slabs with a glass fibre tissue face to limit fibre erosion. The fibre is inert, vermin, rot, and moisture proof, non-combustible and does not support bacteriological growth, packed to a density of not less than 45 kg/m3. The infill has been tested for fire and has a Class spread of flame (as measured to BS476: Part 7: 1971).

Attenuators may be supplied in sections for site assembly by others as required, or as advised by Tek. Nuts, bolts and washers to be supplied by others.

The attenuators have been tested in accordance with BS4718 1971 by an independent consultant. The test procedure eliminates effects due to end reflection, directivity, flanking transmission, standing waves and test chamber sound absorption.

The attenuators have been tested in accordance with BS4718 1971 by an independent consultant.

Where our standard specification does not cover the installation requirements, select the extra features required from the list below. Simply add the suffix to the standard attenuator code e.g. RCPSAT = attenuator for use in saturated atmosphere.

Suffix M: Polyester membrane installed under the perforated metal typically for protection from grease, moisture or oil-laden atmosphere.

Suffix C: Polyester membrane suitable for operating and clean rooms enclosing acoustic infill hermetically, using polyester strip sealant. Acoustic infill retained behind perforated steel sheet or expanded metal hot dipped galvanised after perforation. Attenuators thoroughly cleaned prior to despatch and fitted with sealed end plates.

Suffix PVF: PVF2 anti-corrosion paint may be applied to all internal metal surfaces to offer resistance to corrosive air.

Suffix SAT: Perforated sheet metal or expanded metal retaining the acoustic infill may be supplied hot dipped galvanised after perforation for use in saturated atmosphere. The infill would be encased with a polyester membrane.

Suffix H: High pressure attenuators may be provided constructed in accordance with the recommendations of the HVCA for the construction of rectangular ducts in high velocity air systems.

Suffix S: Crosstalk attenuators may be supplied with spigot connections in lieu of flanges. Attenuator configuration may be selected to customers’ requirements.

Suffix PVC: Plastic attenuators may be supplied for installation in a highly corrosive atmosphere. Attenuator casings and perforated sheet would be manufactured from PVC.

Attenuator Weights / Rectangular – Type RCP

Width
mm
Height
mm
Length
mm
60090012001500180021002400
30030021273642495663
30060034425565758898
600600506687703118134150
6009006087113134155176197
600120086114140165191217243
6001500105135166196226256286
9006006991119141163185207
90090088116152180208236264
9001200116151185220255290325
9001500137178219259300341382
9001800158205252299346393440
120060094122150178207236265
1200900119155191226262298334
12001200144188232275319362405
12001500170221272323375426477
12001800195254313372431490549
1500900143186229273316361406
15001200172223278330383436488
15001500202263325387449511573
15001800231302377443518593754
1800900166217268319370423476
18001200200261322384446508570
18001500234306378450523596756
18001800268350433516600783866
18002100301395488582790883976
180024003354395437748789821086
21001800304399494589798893988
2100210034244955679189810051112
2100240038049861887899611161236
24002400425558850983111614081541

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