Discharge Silencers

Silencieux décharge gaz sous pression Silencieux vapeur Silencieux de détente gaz Mise à l'atmosphère de gaz Vidange de réservoir sous pression vidange de capacité GRTgaz Exxon GE CNIM BOREALIS AIT Stein Stockage sous terrain

Optimal acoustic and mechanical design to guarantee high level performance – up to 70 dB (A) noise attenuation – in extremely safe conditions.

Discharge silencers or Steam Vent Silencers (DAS type) are used to attenuate noise produced by the expansion of air, steam or gas at elevated pressure to atmospheric pressure, the level of acoustic power being up to LW = 160dBA.

The discharge silencers are positioned downstream safety or relief valves in many different industrial applications, in particular in thermal power plant, waste treatment plant, refinery …

Over several decades, with a large reference list in all countries and among major international companies providing an unrivaled experience in the domain, SAI has acquired a complete mastery in the design, fabrication and installation of such equipment.

Acoustic and mechanical dimensions following the international norms are optimized to reach the contractual performance in the safest conditions.

Proven design in extreme conditions

discharge silencer steam silencer pressure GRTgaz Exxon  GE  CNIM BOREALIS  AIT

In general, discharge silencers include two stages:

  • First stage with a diffuser for the gas expansion up to the atmospheric pressure. Mechanical design is calculated according CODAP or ASMEVIII.
  • Second stage with acoustic absorbent is designed to obtain the proper noise attenuation.

With its proven technology, SAI is able to design equipment with extreme process conditions. As example: steam/gas flow rate up to 500 tons per hour, temperature up to 500°C with a pressure at entry reaching 200 bars.

An optimized design

To reach the expected performances, the design of an absorption silence requires the knowledge of additional parameters depending on the process. Among them:

  • Type of gas: air, steam, natural gas, nitrogen, …
  • Volume flow rate (Nm3/h, …)
  • Inlet temperature (°C, °F …)
  • Acoustic performance Lp at 1m (dBA)
  • Pressure at entry or maximum pressure drop acceptable.

Robust fabrication according to international norms

Special care on the fabrication is essential to guarantee total safety for people and goods on site. In particular:

  • Mechanical design according construction code CODAP, ASME VIII DIV.1 …
  • Selection of raw material for elements under pressure: carbon steel P265GH or alloys

SAI discharge silencers are delivered with exhaustive manufacturer documentation set including:  raw material certificates, welding book, result of welding inspection, painting certificate…

Available options

Depending on the installation of the silencers in the industrial application, different options related to design or fabrication are available to meet the needs of the customer. As examples:

  • Flanges or butt weld at inlet
  • Multiple gas/steam entries
  • Vertical or horizontal installation
  • Mounting positions
  • Rain cover or round elbow
  • Protective mesh
  • Calculation notes considering site conditions (wind, seism…)
  • ITP or Manufacturing Quality Plan with customer inspection if required
  • PMI on material
  • Hydraulic test
  • Special painting requirement.