How to implement a successful soundproofing strategy: Fundamental steps and techniques in line with the principles of action


As a matter of fact, noise is regarded as a concrete issue in every industrial facility, and, as a crucial concern, it can easily become hazardous for people around the workspace. For instance, it has been observed that noise may lead the facility’s employees to encounter humming in their ears or have temporary hearing loss. Moreover, an excessively loud environment can easily expose qualified personnel to injury’s risk since noises usually cover alarms or shouted warnings from their co-workers that end-up to be ignored.  

The purpose of the present article is to show many of the options that are adaptable to the most common cases and explore the principles through which noise eradication is obtained when looking into acoustically treating a facility.


Evaluating sources of noise inside our industrial facility

Before ordering an installation, it is advisable to acquire a full understanding of our case. While considering which strategy is the more suitable in order to attenuate harmful sounds, we should first evaluate (1) the source of noise, i.e., the specific piece of equipment that originates the loudest sounds inside the facility, (2) the position and the size of such equipment inside the facility, (3) the operational function of the equipment, as well as its state of preservation. 


Tackling the noise through sound isolation and absorption

Mainly, the noise can be eradicated by isolation or inclusion, or by creating a barrier around the source. Or noise deadening can be obtained by absorption; absorption implies reducing or eliminating echo, reverberation, and amplification within a room, so improving the quality in a limited space, rather than preventing the transfer by separating the source of noise from the rest.


The following solutions are based on the abovementioned principles of action:

  • Acoustic Enclosures are highly effective custom-made solutions that both absorb and block the noise from entering or leaving. Acoustic enclosures are designed to literally enclose any kind of machinery yet are applicable only whether the source of noise can be easily isolated from the rest of the facility. This solution is thus particularly recommended for turbines, auxiliary engines, internal combustion engines and generators sets, mobile generator sets (trailer-mounted) for electric energy production, cogeneration plants, natural gas compression groups, start up and vacuum pumps, blowers, fans, mills, presses, vibrating devices, power transformers and boilers.
  • Comparable to Acoustic Enclosures are Screens and Barriers. While Acoustic Enclosures simply provide protection by isolating the source, screen and barriers are an ideal solution when there is a need to create space between the noise generator and the employees, as they delineate special acoustic shadow-zones. Also, they are composed of sound-absorbing surfaces designed to prevent the increase in noise level towards the source of noise. 
  • Anechoic chambers (AECs) are increasingly used for aircraft engine tests besides being a traditional solution for accurate sound measurement. AECs are indeed perfect when there is a need to completely reduce sound pressure level – to such an extent that reflected signals will be inexistent – in order to acquire the right parameters of precision for measurement.

The importance of receiving a high-quality maintenance process

A further crucial aspect that many tend to underestimate is the state of preservation of equipment that generates noise. Needless to remind that the oldest equipment in the facility needs to be replaced, when necessary, we should take into consideration certain measures, such as oiling and adjusting some critical component on a regular basis. This operation must be carried out by qualified personnel. However, apart from this, it is largely important to rely on professionals in the sector that provide consultancy services and routine checks of the soundproofing applications and make a constantly updated evaluation of their conditions. 

Stopson italiana is the provider you should consider if you are looking for one of the aforementioned solutions. It consolidated itself in the market as one of the main manufacturers of enclosures and control cabins. Moreover, Stopson italiana offers a set of prefabricated anechoic or semi-anechoic chambers, internally treated with standard wedges sized according to the lowest operating frequency, and equipped with a control room.

Potential Solutions for Sound Attenuation in Gas Pipeline Transmission and Compression Stations


Gas pipelines and pipeline transmission have been consolidated throughout the last decades as the most conventional modality to transfer large quantities of natural gas over long distances. Still, as well as acquiring more centrality in geostrategic terms, pipeline networks have become even more complicated in technical ones, so needing the inclusion of additional distribution hubs and compression stations. Compressor stations constitute indeed a key component with a view to concentrate and move pressurized gas along the pipelines.

Moreover, gas compressor stations and pipeline networks occupy a vast area in national territories due to their supplying role. This combination of territorial presence and technical sophistication has led this infrastructure to prevail as one of the most harmful creators of chronic noise pollution.


Sources of noise and noise levels

Technically speaking, the longer the pipeline is, the bigger is the necessity of to increase the pressure used and to encompass additional compression stations. Due to such a variety of equipment placed on this infrastructure, gas pipeline complexes can easily become catalysts of excessive noise generation.

According to several international regulations, as we face a noise level between 79dB(A) and 85dB(A), the source is already violating health and safety standards. Exceeding such standard values, as compressor stations usually do with a noise level up to 100 dB(A), means making a pretty large number of people the subject of noise exposure. As a matter of fact, not only does this put at risk the safety of nearby neighbors – as well as the environment – but also the adjacent infrastructure hosting workers and specialized personnel.


Available solutions and methods of attenuation

The most fruitful strategy when it comes to gas transmission infrastructure is to address noise generation directly at its source. There are several solutions that can be employed to achieve attenuation and stay within safe noise parameters. Among them, multistage control valves can be applied to reduce trim discharge velocity and, consequently, reduce the scale of the noise generated.

However, In-Line Silencers represent the best solution proposed by Stopson Italiana to tackle the issue, which has already been chosen for the installation within the Trans-Adriatic Pipeline (TAP). These peculiar pieces are designed specifically to reduce the noise generated by valves and compressors in piping systems. This typology of Silencers allows to achieve noise attenuation only through reactive components, while do not include any section that would produce an absorbing action. Each Silencer provides an acoustic guarantee approximately equal to 30 dB(A).

The noise level from gas pipelines can be brought back to the increasingly stringent standards also by combining different soundproofing techniques, such as acoustic screens and acoustic insulation components.


Our Service

Any company or institution in charge of manufacturing a gas pipeline complex can rely on Stopson Italiana to provide the system with an efficient soundproofing solution, so avoiding detrimental consequences for surrounding individuals and adjacent infrastructure.

Through our customer management, we can assure a screening consultation to evaluate the scope of your project: how many Silencers your complex needs and at which specific points along the pipeline should be installed to achieve the objectives set previously.

Stopson Italiana managed the delivery of 4 off-base Acoustic Enclosures for a CCPP located in Turbigo, Northern Italy

Major project based on the supply of  Stopson Italiana’s noise control solution to meet the acoustical needs of Turbigo’s CCPP, which has been recently modernized with new key components.


The supply

Since August 2021, Stopson Italiana has been in charge of the supply of 4 Acoustic Enclosures. The 800 MW gas-fired power plant is located in the municipality of Turbigo, in the Milan province, and comprises an 855 MV operating combined cycle unit, composed of two gas turbines and one steam turbine. Stopson Italiana’s soundproofing implantation will be specifically allocated to the gas turbines, generators, and auxiliaries.

Over the last year, the plant has been undergoing general revamping of its main infrastructure. Among the operations that have been carried out, it should be mentioned the positioning of the last component of the boiler chimney, the integration of a new generator, and the installation of an 94.3A gas turbine.


Technical Specifications

The 4 Acoustic Enclosures are engineered according to the components’ technical specifications and processed in Italy with special materials. They present the following configuration in terms of dimensions, manufacture, and noise target:

  • L6,7 m W8,3 m H9,2 m – intumescent coating – 80 db(A) @, 1,5 m from the ground.
  • L5,6 m W2,9 m H3,6 m – intumescent coating – 80 db(A) @,1,5 m from the ground.
  • L16,2 m W5,8 m H6,8 m – intumescent coating – 80 db(A) @,1,5 m from the ground.
  • L10,7 m W9,2 H9,4 – intumescent coating – 65 db(A) @ ,1,5 m from the ground.


Acoustic Enclosures by Stopson Italiana

Stopson Italiana’s acoustic enclosures are designed to satisfy all high-level technical specifications and custom-made requirements to acoustically isolate noisy machinery or create efficient quiet rooms.

Stopson Italiana offers two different products:

  • Acoustic Enclosures for machinery soundproofing, providing total protection against noise by isolating the source.
  • Soundproofed control cabins targeted to safeguard operators from external noise, especially in cases such as in-plant offices, control booths, test cabins, control rooms, and electro-acoustic laboratories.

Acoustic Enclosures stand out as one of the most appropriate solutions with a view to reducing noise pollution for a multitude of sources, including main turbines, auxiliary engines, internal combustion engines and generators sets, mobile generator sets (trailer-mounted) for electric energy production, cogeneration plants, natural gas compression groups, start-up and vacuum pumps, blowers, fans, mills, presses, vibrating devices, power transformers, and boilers.

Stopson Italiana’s acoustic enclosures and cabins can perform noise abatement by 15dB(A) to 50dB(A)+. Typical applications for our Acoustic Enclosures are:

  • Energy production, including gas turbines, steam turbines, traditional industrial and recovery boilers, diesel generators, cogeneration plants (CHP);
  • Chemical and petrochemical plants, including refineries, ethylene production, gasification, etc;
  • Pipelines and natural gas compressor stations;
  • Manufacturing and process industry, for instance, automotive industry, paper factories, printing houses, etc.

⟶ For More Information about Stopson Italiana’s soundproofing enclosures and cabins click here.


Stopson Italiana delivered 172 Vent Silencers for 4 different sections in a Bahrain based Refinery

A full-package solution aimed at obtaining total sound insulation towards different target parts in an Oil Refinery in Bahrain, which has recently undergone an ambitious modernization program.


The project

Stopson Italiana has successfully concluded the delivery of 172 Vent Silencers to be installed among 4 different structural parts of the Oil Refinery in question. The project assists the expansion program that has been taking place since 2018, and it is expected to reach completion prior to the end of 2022.

The Refinery is situated on the island of Sitra, southwest of the capital city Manaba, and produces about 260,000 barrels per day (bpd) of crude oil and 40,000 bpd of low sulfur diesel.


The Supply

The project has been carried out according to the following distribution:

  • n. 2 HP Export Steam Silencers;
  • n. 60 PSIG Steam Vent Silencers;
  • n. 110 PSIG Steam Vent Silencers via a second delivery.

And will cover the following areas: 

  • Safety Systems;
  • Boilers;
  • Blow Out and Clean up;
  • Ventilation Systems.

Most of the Silencers have been provided with a removable internal absorptive pack for easy maintenance and clean-up and a removable rain hood. They are all designed to reach a noise target of 82 dB(A) @ 1 m from the silencer.


What is a Vent Silencer

A Vent Silencer is a soundproofing device aimed at eradicating the adverse noises produced by gas or steam flow while piping into the atmosphere. The noise in question can be generated as a result of the high-velocity flow through the valve and/or a turbulence created around any impedance in the line that may cause restriction or simply change the flow’s direction.

Each Vent Silencer is able to provide an overall attenuation of the noise level to the required sound pressure level criteria at a certain distance from the silencer. 

At the same time, noise reduction can be attained both using a reactive section to attenuate the low frequencies and absorption mean of the high frequency, normally using a sound-absorbing material.

Stopson Italiana engineers its Vent Silencers in Italy, using special materials not only in accordance with all quality standards but also in line with the client’s specific needs thanks to a careful customer management process.

⟶ For More Information about Stopson’s Italiana Vent Silencers click here.


Stopson Italiana supplied 21 vent silencers for PSV and start-up valves as well as for atmospheric blow-down tank to Agios Nikolaos power plant in Greece

A soundproofing comprehensive installation has been recently delivered to assist 826 MW Power Plant (CCGT) at Agios Nikolaos, Greece.



With a 9HA.02 gas turbine, a steam turbine, and a 109FB turbo generator, the Agios Nikolaos power plant is one of the biggest and most efficient combined-cycle gas turbine (CCGT) power plants in Europe. In these types of power stations, several technological methods are employed to control combustion processes. Among these, the traditional usage of boilers and HRSG, which are commonly likely to damage surrounding and inner environments via harmful noise exposition. In fact, safety valves, start-up valves, blow down and flash tank have the tendency to create a very high noise level while discharging into the atmosphere.

Stopson Italiana has designed a specified soundproofing technique in order to provide a high degree of noise abatement. The equipment is silenced through the implementation of separated and well sized silencers, which tackle the source of noise directly in three different operational parts: the pressure safety valve (PSV), the start-up valve, and the atmospheric blow-down tank.


The Supply in details – technical specifications and characteristics

In details, the total supply has been designed in line with the following configuration:

  • 16 vent silencers were designed for PSV, with flow rates ranging from 30 t/h to 300 t/h, temperatures up to 584°C and noise target of 115 dB(A) @ 1 m.
  • 4 vent silencers designed for start-up valve with flow rates ranging from 6 to 260 t/h, temperatures up to 504°C and noise target of 100 dB(A) @ 1 m.
  • 1 vent silencer applied to the atmospheric blow-down tank, performing flow rate 39 t/h, temp. up to 105 °C, 80 dB(A) @ 1m.


Stopson Italiana Vent Silencers

  • Safety Valve (PSV)
  • Relief valve (PRV)
  • Control valve
  • Ejector
  • Startup valve
  • Snort-valve
  • Flash and Blowdown Tanks

⟶ For More Information about Stopson Italiana Vent Silencers click HERE.

stopson blow-off silencers rental

Blow-off Rental Service now available at Stopson Italiana

How to solve temporary noise reduction needs linked to Blow-off Operations

Nearly any high-pressure gas or steam application has the need to purge or evacuate a system at certain times or as a safety measure. When releasing high-pressure gases into the atmosphere, a large amount of kinetic energy is freed due to the pressure difference. The pressure difference causes a dramatic increase in velocity which results in high sound emissions which need to be reduced.

Stopson Italiana Blow-off Silencers are specifically designed to reduce the noise generated by the high differential pressure at the time of a release. The engineering and calculation processes require the following data: medium, mass flow, pressure, and temperature upstream of the valve. The acoustic design covers two main steps: the determination of the non-silenced sound power level and the calculation of the silencer itself.

The sound power level can be transmitted by the valve supplier or inferred by Stopson Italiana using a proprietary framework developed on international standards, and honed by Stopson Italiana’s scientists.

What is a Blow-Off Silencer

The Blow-Off type is a typical expansion and absorption silencer, which is used before the system’s enactment. The principal use is to clean the pipes, removing any solid bodies and residual debris after erection and installation. The expander has a horizontal configuration, located laterally to the body of the silencer, is built with higher thicknesses and usually three metal layers (Case Study: Stopson Italiana’s Blow-off installation in a reconverted paper mill in Italy here).

Soundproofing temporary installations

Profiting from almost sixty years of experience, Stopson Italiana has developed the most efficient silencers with the longest design life. For temporary installations – like steam purging of pipes before plant start-up or boiler/pipe system maintenance – suitable blow-off silencers for rent are now available.

Stopson Italiana’s Blow-Off Silencers cover a wide range of flow rates, pressures, and most common acoustical guarantee targets:

  • 20 t/h up to 250 t/h flow capacity
  • 4 bar to 8 bar Inlet pressure
  • 100 dB(A) @ 1m residual SPL or
    95 dB(A) @ 10 m or
    85 dB(A) @ 30 m

In addition, they are designed to withstand typical blow-off temperatures and feature the following characteristics:

  • Corten A body and structure for a longer resistance at high temperature
  • AISI304 diffuser for clean fluid operations
  • 12”/20” inlet connections with customized adapters available upon request
  • T-joint to avoid larger debris flowing into the diffuser
  • Supporting legs 1.5 meters high from the ground

Stopson Italiana Blow-Off silencers are currently available in three models to cover the entire range of flow rates:

  • SPM 20-70/B: 20-70 t/h capacity range, from 1.2 bar inlet pressure
  • SPM 70-120/B: 70-120 t/h capacity range, from 5 bar inlet pressure
  • SPM 120-250/B: 120-250 t/h capacity range, from 8 bar inlet pressure

Blow-Off silencers can be also tailor-made for Sales against project and Customer specifications with flow rates up to 900 t/h. Stopson Italiana offers an important contribution to the early design process to optimize the system of valves, pipes, and silencers with regard to sizes and costs.


To support plant blow-off operations Stopson Italiana provides a wide range of additional equipment and services:

Engineering Services:

  • Hydraulic Engineering
  • Instruction and Procedures
  • Temporary Piping and Support Design
  • Final Report

Equipment – Sales and Rental Services:

  • Blow off silencers
  • Manual/Pneumatic Target Plate Holder
  • Target Plates
  • Valves
  • Pumps
  • Accessories

On-site Services:

  • Supervision
  • Consulting Services
  • Engineering
  • Representation

Stopson Italiana’s extensive knowledge and experience providing A-Z soundproofing solutions to industrial facilities since 1965, ensure the supply of comprehensive acoustical solutions in support of meeting customer mandatory requirements and their soundproofing objectives, being temporary or permanent.



stopson news soundproofingoil and gas

Soundproofing Solutions for Oil and Gas Industry

Tackling noise-related problems in the Oil and Gas industry


Oil and gas acquisition, refinement, and distribution require the work of several complicated machine networks, some of which produce significant harmful noise. Not only do high decibel levels impact nearby neighbors, but prolonged exposure hurts workers who operate close to the noise sources. This exposure leads to unnecessary long-term health effects that degrade workers’ quality of life. While restricting your hours of operation for noisy blowdowns makes life easier for neighbors, you need further measures to protect your workers.


Noise intensity is measured in decibel units (dBA). The dBA scale is logarithmic; each 10-dBA increase represents a tenfold increase in noise intensity. Human perception of loudness also conforms to a logarithmic scale; a 10-dBA increase is perceived as roughly a doubling of loudness.

Thus, 30 dBA is 10x more intense than 20 dBA and sounds twice as loud; 40 dBA is 100x more intense than 20 and sounds 4 times as loud; 80 dBA is 1 million times more intense than 20 and sounds 64 times as loud.

Distance from the source and duration of the exposure are also to take into account.

In general, we can say that, subjected to 45 dBA of noise, people cannot sleep. At 120 dBA the ear registers pain, but hearing damage begins at a much lower level, about 85 dBA.


​​With oil and gas operations producing so much noise, any noise control products have to be customized to each worksite to have their maximum effect.

Due to the various compressors, pumps, furnaces, blowers, extractors, and other equipment placed on this kind of complex, it comes as no surprise that the possible solutions are different according to what the project is trying to accomplish.

Here are some examples of soundproofing products:

  • Acoustic Cabins and Enclosures

Acoustic Enclosures are available for generator sets, pump sets, compressors, and other machines and installations, while Cabins are usually more suited for mud pump rooms, engine rooms, or complete driller cabins. Both can be designed for customers’ particular requirements so that it is a perfect fit for their plant.

  • Ventilation sets, silencers and acoustic louvres

A ventilation set includes an air inlet and air outlet system for the ventilation of heat radiation, air inlets for combustion air, and eventually a purge system. Possibly including Silencers, acoustic louvers, heat tracing, demister panels, filtration systems, dampers, anti-condensation heaters, and redundancy.

Stopson Italiana available silencers:

  1. Vent Silencers
  2. Engine Exhaust Silencers
  3. Intake & Stack Silencers
  4. Ventilation & Duct Silencers
  5. In-line Silencers
  • Sound insulating doors

Soundproofing doors with high sound insulation values and possibly fire resistance properties. With a clean design and fully customizable, they are therefore very appropriate to place anywhere where noise insulation is essential.


Following an initial consultation path with a leading industrial and environmental noise control manufacturer, is the quickest and most effective way to solve complex noise mitigation challenges like the ones faced by Oil and Gas professionals.

Stopson Italiana’s extensive knowledge and experience providing turnkey industrial noise control solutions to the Oil and Gas industry since 1965, ensure the supply of comprehensive acoustical solutions in support of meeting customer mandatory requirements and their soundproofing objectives.


General implications of noise control in industrial environments

Industrial noise considerations and solutions

Industrial businesses can be a primary cause of noise pollution to the environment, which is why it is important to install acoustic systems into the building. Having appropriate soundproofing solutions within the complex can reduce the loud noises that heavy equipment can emit.


Industrial processes are often very noisy as the operations and equipment to process and produce industrial outcomes often include heavy machinery with limited barriers to restrict equipment noise from carrying beyond the confines of the installations.

The introduction of stringent health, safety, and environmental regulations has led to an increase in importance when considering noise control around industrial processes.

The aim of these regulations is to ensure that a worker’s hearing is protected by preventing them from being subject to high levels of noise which could cause long-term hearing damage.

From an environmental point of view, these regulations have been put in place to keep industrial facilities’ property sound levels below the required noise levels that vary by zoning.

Why do you need industrial soundproofing

There are various reasons as to why you might need to have noise control in your industrial premises. External and internal noise levels need to be kept to an acceptable level, and industrial soundproofing products offer solutions to excessive noise problems for both the environment and workers.

Some plants operate within residential areas, so it’s important to keep external noise to a minimum in order to prevent noise complaints and upset from the local community. Other industrial complexes use loud machinery that goes above the acceptable noise level, this can cause problems internally. Such issues need to be addressed as best as possible, which is why industrial noise control is a necessary asset to have.

Failure to comply with noise mitigation control could see the owner’s fighting legal battles and compensation claims.

Industrial Soundproofing Considerations

There are three basic elements in any noise control system:

  • The source of the sound
  • The path through which the sound travels
  • The receiver of the sound

In many situations, of course, there are several sources of sound, various paths for the sound, and more than one receiver, but the basic principles of noise control would be the same as for the more simple case. The objective of most noise control programs is to reduce the noise at the receiver. This may be accomplished by making modifications to the source, the path, or the receiver, or to any combination of these elements.

The purpose of the noise control procedure may be to prevent hearing loss for personnel, to allow effective face-to-face communication or telephone conversation, or to reduce noise so that neighbors of the facility will not become intensely annoyed with the sound emitted by the plant. The engineering approach is often different in each of these cases.


Noise control solutions

At the source

Modifications at the source of sound are usually considered to be the best solution for a noise control problem either being the most difficult approach. The noise at the source strictly depends on the design process the machinery has been through and in some cases, on its maintenance as well. For example, excessive noise from a roller bearing in a machine may indicate wear failure in one of the rollers in the bearing or, there may be areas, such as panel coverings, that vibrate excessively on a machine.

To determine whether this approach is feasible, the engineers would need in-depth information about the process in which the equipment is taking place and on the machine itself.

On the transmission path

Modifying the path through which the noise is propagated is often used when modification of the noise source is not possible, not practical, or not economically feasible. For noise sources located outdoors or indoors, the transmission path may be modified by placing a wall or barrier between the source and receiver. The use of a barrier will not be effective in noise reduction indoors when the sound transmitted directly from the source to the receiver is much less significant than the sound transmitted indirectly to the receiver through reflections on the room surfaces. In this case, A very effective noise control procedure is to place an acoustic enclosure around the sound source or to arrange the receiver in a soundproofed cabin. The exhaust noise from engines, fans, and turbines is instead controlled by using mufflers or silencers in the exhaust line for the device.

At the receiver

The human ear is the usual ‘‘receiver’’ for noise, and there is a limited amount of modification that can be done for the person’s ear. One possible approach to limit the noise exposure of a worker to industrial noise is to limit the time during which the person is exposed to high noise levels. In other cases, to reduce the sound level to which the workers are exposed, hearing protectors (earplugs or acoustic muffs) can be effective, preventing noise-induced hearing loss in industrial environments.


What are the benefits to apply soundproofing solutions to your industrial facility?

  • Provide a safe work environment by helping to reduce accidents caused by poor communication
  • Prevent hearing loss
  • Increase productivity by decreasing distractions
  • Reduce complaints from neighboring businesses and residents

Soundproofing comes in many forms and does a great deal of work to create an environment conducive to productivity, effective communication, and privacy. No matter the industry, taking the time to factor the sonic landscape of a property into your plans will pay dividends in the future.

Industrial plants are often complex facilities, requiring individualized noise control solutions. For every reason why you would need to solve for each of the many different types of industrial noise, there exists a solution. As such, it’s important to consult experts in the field of industrial acoustics to solve for each individually.

Stopson Italiana has worked nationally and internationally for 50+ years with plant processing engineers and their consulting teams to provide accurate and cost-efficient, site-wide noise assessments and mitigation solutions for industrial sectors across many industries.




Engineering Noise reduction for Hydroelectric power plant

Steps that can be taken to help mitigate excessive noise in the hydroelectricity industries

Since the amount of machinery, such as turbines, air compressors, and rotors associated with each generating unit, noise production in Hydroelectric power plants is high.


The human body has few resources to defend itself from noise. This alteration can create many effects on the human organism including contemporary stress that changes working behavior, produces low productivity, high rates of absences from work and obviously hearing loss.

Hydroelectric Power Plants generate lots of power and sometimes excessive noise. Among hydropower plants, there are some built more than half a century ago, and the noise was not factored into plant design. To confirm that, most power plants have hard concrete walls that magnify sound. What happens is that energy doesn’t go anywhere, it just bounces off the walls. And that tends to increase the noise levels even way above the source.

To capture the noise profile and target even the subtlest reverberations, Soundproofing experts must perform acoustic surveys using cutting-edge analytical equipment to isolate hazardous noise sources.


“In marine vessels and submarines stationed across the globe, noise suppression technologies have been successfully used in engine rooms since the 1970s. They’ve put a lot of effort into making sure that a marine vessel is very quiet, so their engine rooms are really similar to a hydropower plant, with thick walls, and water all around. There may be a connection, relationship there and sure enough, it was. So, choosing a partner with strong expertise in the marine sector will help to solve noise concerns in these peculiar power plants.” LEARN MORE

Soundproofing Hydroelectric Plant

To mitigate noise, soundproofing experts must analyze and design solutions for treating the noise at the source (if possible), but, due to plant complexity, frequently the plan involves treating the transmission path to the receiver.

While designing soundproofing solutions, maintenance considerations must be taken into account in suggesting noise control techniques for hydroelectric power plants. Materials and methods need to be as maintenance-free as possible and still able to achieve the desired noise reduction level. Used materials also need to meet safety regulations for fire, smoke, and toxicity.

Here are some examples of soundproofing solutions for Hydroelectric stations:

  • Damping

Damping is a term used to describe applying a viscoelastic material to a structure to reduce the vibration of that structure. Since noise (acoustical energy) can be generated by a structure that vibrates and is an efficient radiator, reducing the surface velocity due to damping will also reduce noise.

  • Sound Absorption

Silencers are the most well-known example for absorbing energy to reduce noise. By adjusting the specifications of the silencers, acoustical energy at certain frequencies will be “trapped” within the silencer body and will dissipate.

  • Acoustic Barriers

The concept behind an acoustic barrier is simple. By placing a solid wall (barrier) between the sound source and the receiver, the acoustical energy gets reflected back to the source and will not reach the receiver, thus reducing overall noise. Acoustic enclosures and barriers are ideal for spaces where frequent access is required, yet a significant reduction in the transmission of acoustical energy is desired, such as a turbine pit.


Included in the supply are the previous surveys, the design, the construction, the installation, and the photometric measurements of an acoustic booth…(READ MORE)


Because of the variety of contributing noise sources in Hydroelectric plants, there is no one-size-fits-all solution. Due to the complexity of the acoustical challenges this sector faces, a tailored solution is required to ensure the deployment of effective noise control systems.

Following an initial consultation path with a leading industrial and environmental noise control manufacturer, is the quickest and most effective way to solve complex noise mitigation challenges.

Stopson Italiana has worked internationally with plant processing engineers and their consulting teams to provide accurate and cost-efficient, site-wide noise assessments and mitigation solutions of industrial sectors such as petrochemical complexes both large and small.


Industrial Soundproofing for Marine Engines

Marine noise considerations and solutions

Safety first, safety always. The primary purpose of installing industrial sound proofers in marine engines is to ensure minimal exposure of people (personnel to noise hazards).

By effectively applying sound proofers to marine engines, chronic hazards like partial deafness, tinnitus, threshold shift in hearing, and noise-induced hearing loss can be effectively avoided.

The maritime industry bears certain similarities to the aviation industry regarding compliance with full safety regulations by local and international regulatory bodies. This may be attributed to the high risks involved and the nature of their operations.
Special noise safety laws and regulations have been provided and reviewed as deemed fit within the industry over the past couple of years. Expectedly, strict implementation of these laws is expected from the employers and employees in the maritime business. This implies that compliance with these regulatory standards is a moral responsibility for all shareholders.

Industrial soundproofing of marine engines is one of the many recommendations by noise hazard safety experts adopted into the maritime standards and policies. Marine engines generate excessive noise above the acceptable limit of sound (< 85 decibels). It has necessitated the design of marine engines with soundproofs and the need for alterations to allow for the installation of soundproofs in marine engines originally lacking soundproofing.

Sounds and an excess of it (noise) results primarily from the amphibious engines and secondarily from engines in onboard mechanical or electro-mechanical systems. Both noises are undesired and require the development of methodologies to mitigate them.

How to Mitigate Yacht Sound Pollution with Soundproofing

Experts of noise management and several organizations have developed and mastered containing noise from yacht engines. Some of the most effective noise management techniques are:

  1. Usage of soundproofing barriers:

An adhesive-like material that can easily be fitted like a chewed gum is placed on a body of a plastic pipe. These soundproofing barriers are installed inside the yacht cabins and engine rooms to mitigate the resulting noises.

  1. Use of noise isolation systems:

Noise isolation systems are technological products designed to mitigate potentially harmful noises produced within an area drastically. These devices are strategically positioned and are more effective with an area to a number of device ratio.

  1. Sound Dampening Materials:

Since vibrations from moving parts of marine engines are a major notorious mechanical phenomenon that produces noise, experts use sound dampening materials to lag engine parts, sittings of these engines, nuts, and screw meet points.

  1. Anti-drumming mats:

Excessive noise and vibrations from yacht occupants and engines are managed by using anti-drumming mats made by heavy acoustic foil. These specially made mats are placed at doorways to help curb excessive noise pollution.

  1. Fabrication:

An age-long system of noise control for marine engines is an engineering control that involves the design, fabrication, and installation of a sound-proof cage-like structure around the engine (primarily) and sound-proofing walls of the yacht engine room.

  1. Complete Soundproofed Exhaust system:

Dry and Wet custom exhaust systems are probably the most effective way to soundproof marine engines. Made from Stainless Steel or GRP (Glass Reinforced Polymer).

The difference between Dry and Wet exhaust system

  • Dry Exhaust:

Compare a dry exhaust to the exhaust pipe of the car: a pipe with a flexible connecting piece on the exhaust manifold, discharging the exhaust gases directly to the outside air. A dry muffler is often required to muffle the noise. Cooling water from the engine is added to the exhaust system either externally or at a much later stage. The tubes and pipes are often made of steel to prevent them from melting due to the high temperature. It is a simple system, but with two major drawbacks: it emits intense heat of up to 600°C at the source, and it produces more noise.

  • Wet Exhaust:

It is recognizable by the manifold that is mounted on the engine. This is often custom-made from GRP (Glass Reinforced Polymer). The heated cooling water in the engine is around 60-90°C when it leaves the engine, so it can be perfectly used to cool the 600°C exhaust gases. Water and gases are often not yet mixed in the first section of the exhaust pipe. That is to prevent the water from entering and blocking the gases from exiting the engine. Gases must be able to exit the engine smoothly so as not to compromise the engine performance. At a short distance from the engine, the gases and liquids come together and exit the engine.

To find your best-fitting complete exhaust system to soundproof your engine you might want to take advantage of the experienced industry-leading company SilencERmarine.

SilencERmarine develops, manufactures, and market throughout the world stainless steel and GRP (Glass Reinforced Polymer) silencers, complete exhaust systems (R.I.Na. – Italian Naval Registry, D.N.V., and Lloyd’s Register approved as well as any other approvals required), and all components and accessories needed to install these.

Benefits of Soundproofing

It is important to note that failure to effectively soundproof onboard engines can rack up serious consequences. Some of these consequences may include the deteriorating health of the crew, who are often the first victims of sound pollution to occupational hazards due to longer exposure to noise emanating from onboard engines.

The resultant effect may see yacht owners paying litigation and compensation fees. In addition, non-compliance to regulatory noise limit aboard could incur strict penalties and fines from respective authorities.

The benefits of soundproofing a typical yacht outweighs putting up with the noise encountered during sails. Some of these advantages are:

  1. Improved reputation for yacht owners which is good for business.
  2. Increased ROI by implementing reliable soundproof materials such as Steel dry silencers.
  3. Compliance with regulatory standards thanks to top-tier industry GRP silencers and separators.
  4. Easy detection of mechanical or operational anomalies due to the absence of noise.

Methodologies and Materials to Mitigate Noise in Onboard Engines

The application of these soundproof materials is largely dependent on the design and location of the yacht engine. Since onboard engines could be integrated inside or in the outer parts of the yacht, the preferred application of soundproof materials varies. IMO (International Maritime Organization), the custodian of the Safety At Sea (SAS) internationally, does not compromise its stance regarding maritime safety. For more specificity, noise control is not given less attention.

Sanctions are often meted on violators in a bid to ensure reduced safety challenges on the seas. To avoid such sanctions and penalties from regulatory bodies such as IMO, simply ensure to install sound proofers around marine engine parts and even the yacht’s cabins. If you need expert advice on your soundproofing needs, you can contact

Ultimately, maritime investors, yacht owners, captains, staff crew, visitor crew, and other stakeholders are expected to report cases of noise pollution to relevant authorities as this may be injurious to the health and well-being of the occupants. The health and safety of those on board should be considered as primary and most important. Industrial soundproofing for marine engines is fundamental and should be encouraged internationally and otherwise.

National policymakers should consider creating regulations that border around efficient soundproofing practices.