Noise Control
Custom-engineered silencers for high-pressure gas blowdown, depressuring and start-up venting: staging the pressure letdown and absorbing the jet noise so an underexpanded sonic vent meets its boundary limit without starving the relief system of capacity.
Exterior Interior See It Inside
Drag the handle to compare the closed shell with the cutaway and see how one violent expansion is broken into many small, quieter jets.
A high-pressure vent silencer works in two stages. A multi-stage diffuser takes the pressure letdown in controlled steps, replacing a single underexpanded sonic jet with many small jets at moderate pressure ratios, which generate far less sound energy and shift what remains to higher frequencies. A downstream absorptive section, lined with acoustic fill behind perforated facings, then soaks up that broadband, high-frequency energy before the gas leaves the outlet. Shell diameter follows from velocity control, so the silencer never sets a self-noise floor under the level you need.
Built To Your Specification
There is no catalogue table for a vent silencer. Change the gas, the temperature or the target and the same mass flow needs a different unit. We size each one from your process data against a validated aero-acoustic calculation.
We take your peak mass flow and blowdown profile, the upstream pressure and temperature, the gas composition, and the noise limit (its level, location and origin), and define the required insertion loss across the spectrum.
Engineers size the diffuser stages and absorptive section to pass the peak flow within the allowable pressure drop, holding passage velocities low enough that the silencer’s own flow noise never sets the floor.
The unit is fabricated and quality-checked at our own facility, in materials rated for the gas stream and the temperatures and forces of a blowdown.
Units are shipped, installed and verified against the noise target, with documentation handed over on completion.
From the Knowledge Hub
Mass flow, pressure ratio, gas properties and the noise target all interact, which is why there is no catalogue table for high-pressure venting. Here is what each driver does to the silencer, and the data to have ready when you specify one.
Read the articleCapabilities
What separates an Axces vent silencer from an off-the-shelf part.
Acoustic
Diffuser staging plus absorptive treatment tuned to the broadband, high-frequency noise of a choked vent, sized to the gap between the bare-vent level and your boundary target.
Backpressure
Allowable pressure drop is treated as a safety constraint, not a preference: built-up backpressure that could de-rate the relief or blowdown device is engineered out, not discovered on site.
Process
Molecular weight, specific-heat ratio and temperature drive the sizing. Air, natural gas, steam or hydrogen-rich streams each get materials and acoustic fill matched to the duty.
In-house
Acoustic and mechanical design from a single source, engineered together with the relief and blowdown system rather than in sequence, one responsible partner for noise and flow.
Applications
Any blowdown, depressuring or start-up vent that carries a noise requirement, each sized to its gas conditions and the limit at the governing location.
Oil & gas
Emergency depressuring, pipeline and vessel blowdown vents on refineries, terminals and compression stations, sized to the choked-flow noise of the relief case.
Read moreIndustrial & EPC
Start-up, purge and continuous letdown vents across chemical and process plant, delivered to EPC contractors as part of a single scope of supply.
Read morePower generation
High-pressure steam blowdown and boiler safety-valve vents, where a sonic discharge would otherwise breach the site-boundary limit.
Read moreMarine & offshore
Depressuring and relief vents on offshore platforms and vessels, engineered for compact, elevated discharge arrangements.
Read morePressure control
Where venting is as much a pressure-control duty as an acoustic one, the same staged-diffuser approach manages the letdown in controlled steps.
Read moreSend us your peak mass flow, pressure ratio, gas data and the noise limit with its location. We’ll come back with a sized silencer and the insertion loss it delivers.
