Stopson Italiana’s solutions soundproof the restored historical newsprint mill in Mantua.
Beyond Power Generation and Oil and Gas, Stopson Italiana’s soundproofing solutions embrace the manufacturing sector as a whole.
One of the last relevant projects concerns the soundproofing of the recently converted paper mill in Mantua, Lombardy, performed with two types of silencers for different services: Blow-Off and Steam Vent.
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 an horizontal configuration, located laterally to the body of the silencer, is built with higher thicknesses and usually three metal layers. It consists of a pipe with a closed end with a certain number of large holes to allow proper expansion of the fluid and any debris passing through the holes with no damages at the same time.
The silencer – which has a size of Ø 2500 mm x H 7000 mm – has been conceived to achieve a sound pressure level of 100 dB (A) at 20m, which is more challenging than the ordinary soundproofing capacity for this type of silencers.
Discharge conditions: maximum flow rate 135 T / h at 330° C
Due to its capabilities, the typical applications regard the pipes blowing and cleaning processes, as well as the resistance to huge water flows.
The second silencer – that was supporting a larger supply delivered by our partner Tecnoterm Energy S.r.l. – comprised the design, production and installation of a Steam Vent Silencer (SPM model).
The model chosen was specific to reduce the sound emissions generated by the medium and low pressure valve groups.
Produced with a dimension of Ø 2200 mm x H 2900 mm, the silencer provides a residual noise level of 85 dB (A) at 1 m, with a sound attenuation of 50 dB(A) (delivery scheduled for the end of January).
Discharge conditions: Maximum flow rate 135 T / h at 160 ° C for the low pressure; 430° C for medium pressure.
The typical applications of this type of silencer are the Revamping Mill Plants and Cogeneration Plants.
Our offering for Paper Mill application
Stopson Italiana has a wide range of product for Paper Mill applications, including Air Filtration, Duct Silencer, Acoustic Enclosures and Barriers, Steam Vent Silencers.
Our Vent Silencers are designed to reduce noise level of exhaust piping to the atmosphere for pressurized gaseous fluids, such as air, vapour, natural gas, nitrogen, oxygen, carbon dioxide, etc. They can be installed downstream any device acting as a link between a container of pressurized gaseous fluid and the atmosphere. The vent silencer can also provide high or low back pressure relief for the system ensuring proper operation.
Vent silencers can be reactive, absorptive or combined type depending on applications and required attenuation, which can reach as much as 75 dB(A).
Typical Applications for vent silencers are:
Safety Valve (PSV)
Relief valve (PRV)
Start up valve
Flash and Blow Down Tanks
Stopson Italiana’s offering for plant Blow-off cleaning does also include additional services and materials as described below:
Blow-off Equipment, including Silencers, and Supervision from Stopson Italiana supported New Assiut and West Damietta Single to Combined Cycle Power Plants conversion in 2018
Stopson Italiana has successfully completed the supply of steam blow-off silencers and cleaning equipment, including pumps, valves, spectacle flanges, instrumentation and pneumatic target plates system, and provision of supervision services for the blow-off operations of two Combined Cycle Power Plants (CCPP) performed in parallel.
The 230 t/h capacity silencers are equipped with 16 bara design pressure diffuser in a carbon steel casing 6 meters high with 2.5 meters diameter, capable to achieve a residual sound pressure level of 90 dB(A) at 3 m from equipment. Stopson Italiana’s blow-off silencers are based on a combined reactive and absorptive principle for noise reduction: the gases expand to atmospheric pressure through an horizontal large-holes perforated diffuser, providing a first step in attenuation while allowing any debris to flow out, then evolves into a sound-absorbing lining section to further contribute to reach required noise residual level.
The 1 GW New Assiut plant and 500 MW West Damietta plant have gone through a substantial upgrade with the addition of steam turbine modules recovering heat from existing Gas Turbines. This 750 MW addition over the two plants will take the total capacity to 2.25 GW, further contributing to helping meet the increasing demand for power in the country.
Stopson Italiana’s offering for plant Blow-off cleaning does include a various range of products and services:
With more than 50 years of activity in industrial soundproofing, Stopson Italiana will bring its expertise gained in 20 thousand projects worldwide, most of them accomplished within the Oil & Gas sector.
The Milan based company will present the technological features of its soundproofing products – like Vent Silencers, Engine Exhaust Stack, In-line Silencers and many more, in the world’s leading conference and exhibition for the European Power Generation industry.
For all those attending, Stopson Italiana will make available its technical expertise to support any demanding requirements to develop new sound-proofing and noise abatement solutions in the Gas Industry.
For over 45 years, the Gastech exhibition and conference has been at the forefront of the international gas, LNG and energy market. This world renowned event is regarded as the most significant meeting place for upstream, midstream and downstream gas and LNG professionals, where they convene to do business.
Visit us at Gastech Barcelona, Spanish Pavilion – Booth G160!
Gastech has fast become a next generation energy event, hosting major NOCs, IOCs, integrated energy companies, global utilities, EPC contractors, shipbuilders, pipeline companies, manufacturers, technology providers and service companies all of whom play an active role in the global energy value chain. Gastech has been at the forefront of the gas and LNG business for more than four decades, with each edition being supported by a host partner since 2002.
With more than 3.500 International Conference Delegates, 1.200 C-Level & Ministerial Attendees and 350 speakers (regarding upstream, midstream and downstream value chains), the event encompasses also a Conference consisting of the Plenary Stage, Strategic conference and Technical conference streams, and four Specialist Conferences.
Gastech’s four-day, multi-streamed conference is regarded as the industry’s most important platform to debate and discuss the global issues and challenges facing the gas and LNG community in 2018 and beyond. The program features ministerial sessions, CEO panel sessions, and commercial sessions, along with the world’s largest technical conference.
Gastech 2018 will take place in Barcelona (Fira Gran Via), September 17-20, and Stopson Italiana will be exhibiting in the Spanish Pavilion – Booth G160.
Stopson Italiana will present the technological features of its soundproofing products in the world’s leading conference and exhibition for the European Power Generation industry
In its inaugural year as Electrify Europe, the re‑imagined event (previously “Power Gen”) will be dedicated to the convergence underway between the power generation and the transmission and distribution sectors, driven by digitalization, decarbonization, decentralization and electrification.
For all those attending, Stopson Italiana will make available its technical expertise to support any demanding requirements to develop new sound-proofing and noise abatement solutions in the Power Industry.
Visit us at EE2018, Italian Pavilion – Hall A Booth R52
With the aim to attract over 11.000 delegates and attendees from more than 85 countries, Electrify Europe represents the industry’s premier conference and exhibition dedicated to the power generation, renewable and alternative energy and transmission and distribution industries. In this year of rebranding, the trade show has extended its conference program including keynote and plenary sessions addressing key issues affecting the sector. Among these: E‑mobility, Cybersecurity, AI, Blockchain, Demand Side Response and Energy Storage. Read full program here.
This year, Electrify Europe will address such topics as:
Transforming power economics & management
Advances in power generation technology
Operations & maintenance in a digital age
Sustainability & environmental protection
Energy storage & e-mobility
Intelligent infrastructure & cybersecurity
Empowering the customer
Distributed energy & systems
Since 1965 Stopson Italiana has been considered one of the largest provider of noise control solutions such as silencers, enclosures, vent equipment and test facilities for any industrial applications.
The Electrify Europe will take place on 3 days from Tuesday, 19 June to Thursday, 21 June 2018 in Wien and Stopson Italiana will be exhibiting at Hall A Booth R52 (Italian Pavilion)
How and what you need to know to soundproof properly your plant
Some basics about noise
Noise is commonly defined as unwanted sound. A typical noise control problem includes three basic components: the noise source (machines, fans, pumps, processes etc.), the receiver (persons subjected to the noise); and the path (the route the noise travels between the source and the receiver indoors or outdoors).
Noise can be classified in two different forms: airborne and structure-borne.
The first one goes from a source to a receiver as a differential in atmospheric pressure, traveling in all directions. Structure-borne instead is unwanted vibration, which is transmitted from a vibrating source to a receiver through a solid material and regenerated as airborne noise. Once the three main elements (source, path and receiver) have been identified, four ways can be adopted to control the noise: absorption, barriers (blocking), damping and vibration isolation.
Perhaps the greatest single contribution of unnecessary noise is the lack of proper maintenance and corresponding preventive maintenance intervals. Equipment that is poorly maintained eventually becomes inefficient. One manifestation of inefficiency is noise (misdirected energy), which, ultimately, becomes the subject of replacement. Typical energy wasters and noise producers are:
Improperly aligned belts
Unbalanced rotating parts
Reciprocating striking parts
Insufficiently lubricated parts
Contact between moving and stationary parts
Compressed air leaks
Vibrating sheet metal, such as streamlining
Improperly adjusted linkages or cams
How to choose the most appropriate Steam Vent Silencer provider
Which are the most relevant data to be considered in order to identify the correct roles within the supply chain of acoustic manufacturers. Understanding all of the factors involved could simplify the selection of the rightest vent silencer for the application required. But first, it’s important to introduce vent and blowdown silencers, reviewing the factors involved in predicting the noise generated by high-pressure vents.
Here below a list about the blowdown and vent applications that require silencers:
Steam venting in power generation applications
Process control and relief valves in industrial applications
Pipeline blowdowns and Natural Gas compressor station
Blowdown tanks and autoclaves
Bypass valves on blowers and compressors
Discharge of high-pressure gas to substantially lower pressure environment (atmosphere).
Steam ejectors and hogging vents
Vent Silencers and their applications
The terms “vent silencer” and “blowdown silencer” refer to the relative application for which each one is used. For both of them the design is similar, since we refer to vent silencers when being used to vent at a constant flow rate, for a period of time. The word silencer is instead referred to as blowdown, when they are blowing down a finite volume of gas starting at a high pressure, and ending at a low pressure over a given time. Vent silencers are sized for constant flow and blowdown silencers are sized for maximum flow.
Vent silencers find wide applications in high pressure vents, steam vents, safety relief valve outlets, system blow downs and purge outlets etc. Vent and blowdown noise is a function of upstream pressure and temperature, type of gas being vented, the valve size and type, plus the effect of downstream piping.
Stopson Italiana designs and manufactures high quality Vent Silencers that attenuate the high noise produced by the expansion of Gas, Steam or Air at elevated temperatures to atmospheric pressure.
When it’s required the installation of a Vent Silencer, here below all the data required in order to obtain a precise offer:
Application (Vent, Blow down, Relief)
Fluid Composition (Steam, Gas, Air)
Molecular Weight or Specific Gravity
Process conditions upstream of valve and units (lb/hr, SCFM, ACFM)
Temperature Pressure (P1)
Atmospheric pressure ( Pa ) / Temperature (T2)
Line size between valve and silencer
Line size from silencer discharge
Attenuation required (silencer performance)
Allowable pressure drop
Noise Generated by High-Pressure Vents
Over the years, there has been a good deal of work done in the field of predicting the noise generated by the high-pressure venting of gases.
Factors Influencing Noise Generated by High-Pressure Vents:
Mass flow – the higher the mass flow, the noisier it becomes.
The type of gas and its molecular weight/specific gravity – lighter gases are noisier.
Temperature – higher temperatures result in lighter gas flows, and therefore, higher noise levels.
Upstream versus downstream pressure – the higher the upstream pressure is relative to downstream pressure, the louder it will be.
Choke flow (critical flow or sonic flow) – occurs when upstream pressure is roughly two times or greater than downstream pressure, making things much noisier.
Orifice/opening size of valves, vents, orifice plates, diffusers, etc. – larger diameters result in low frequency noise, while smaller diameters produce higher frequency noise. For instance, diffusers create a shift in the noise spectrum from low frequency (one large vent opening) to high frequency (many smaller openings), which is much easier to attenuate.
Elements Creating Noise in High-Pressure Venting Systems
The noise at the end of a high-pressure vent pipe is a combination of the noise generated by the high-pressure-drop elements in the system. Essentially, any element that has a high-pressure drop across it or large change in area will create noise and should be included in the noise model to accurately predict overall noise level.
The major elements that create noise in high-pressure venting systems are:
Pressure relief and control values – present in virtually all venting systems.
Vent pipes/nozzles – last element in venting systems, except for those using high-pressure silencer diffusers.
High-pressure silencer diffusers – when included, usually designed to provide a specific backpressure at the rated flow (sometimes used as fail-safe device).
Orifice plates – included in many systems as a flow regulator or fail-safe device.
Enlargers (reducers), headers and abrupt transitions – included in pipe systems for various reasons. Shock Noise Versus Turbulent Mixing.
There are two phenomena that produce noise in a high-pressure venting system:
Shock noise – occurs when a choked flow condition exists
Turbulent mixing – caused by the ripping of the air as the vent gas decelerates to lower velocity, such as the atmosphere. Shock noise is the louder of the two. By adjusting the elements in a piping system it is possible to reduce the shock noise by reducing the magnitude or quantity of choked flow conditions present. Turbulent mixing, on the other hand, is always present, though less of an issue.
Industrial silencers: an increase of demand due to a more strict regulation for industries
An integral part of today’s industrial process and ventilation systems, industrial fans, blowers, and compressors are leading causes of noise problems. If unaddressed, these issues can lead to health and safety concerns, as well as environmental regulation violation. With the tightening of noise regulations, industrial facilities are required to stay in compliance with regulations. Industrial silencers are typical being used to attenuate noise coming from intake and exhaust systems of industrial facilities. These silencers may be built in limited space. Inside an industrial area, fan installation is one of the most predominant source.
Industrial silencers are engineered to control noise in specific applications, and can alleviate problems in work facilities. With more than 50 years of experience Stopson Italiana soundproofed plants in a broad range of installations, such as:
Gas Turbine Engine Exhaust Silencers
Silencers are required for almost all installations that particularly include gas turbines and heat recovery steam generators. Our Gas Turbine Exhaust Silencers are especially designed to work in an environment where they are simultaneously exposed to high temperatures and to high velocity turbulent flow.
Stopson Italiana provides full custom engineered Inlet Exhaust Silencers for Gas Turbines, DG sets Turbo Compressors and Turbo Blowers. They entail complete solutions in the field of Machinery filtration and acoustic solutions for Gas turbines and compressors.
Stopson Italiana Gas Turbine Silencers provide the ideal solution to keep noise at a manageable level, while maintaining the operating efficiency of your turbine intake system.
Stopson Italiana designs and manufactures all types of discharge silencers in compliance with the international quality standards. Our discharge silencers are very much effective in reducing the noise for entire systems that receives air for heavy engines & turbine.
Stopson Italiana engineers have been designing application-specific products and services for industrial plants and processes since 1965. Each product manufactured is tested and inspected to meet all applicable industry standards in terms of quality, longevity and safety.
Stopson Italiana has just achieved the new ISO 9001:2015 certification, pointing its ethical awareness towards a full compliant and updated Quality Management System.
The certification highlights the company’s focus on pursuing a policy of continuous improvements, constantly keeping all its operating units up-to-date, ensuring customers affordable performance, products and services. “We firmly believe in teamwork – said the CEO of Stopson Italiana -, for this reason, while adopting this new certification we ensure that stakeholders, such as customers, staff, suppliers feel more involved around common objectives”. Defined by International Organization for Standardization, and provided in Italy by ICIM SpA (Istituto di Certificazione Italiano per la Meccanica), ISO 9001 is a standard that sets out the requirements for a quality management system. It helps businesses and organizations to be more efficient and improve customer satisfaction, sharing the culture of quality for the industrial mechanical sector. The new version of the standard, ISO 9001:2015, has just been launched, replacing the previous version (ISO 9001:2008).
ISO 9001:2015 specifies requirements for a quality management system when an organization:
needs to demonstrate its ability to consistently provide products and services that meet customer and applicable statutory and regulatory requirements;
aims to enhance customer satisfaction through the effective application of the system, including processes for improvement of the system and the assurance of conformity to customer and applicable statutory and regulatory requirements.
The main difference with the previous certification
The most noteworthy change to the standard is represented by its new structure. In facts, ISO 9001:2015 follows the same overall structure as other ISO management system standards (also known as the High-Level Structure). As a consequence it is more expedient using multiple management systems. Another difference is the focus on risk-based thinking, since this new version gives it increased prominence.
Contextual Analysis as a new core issue
An other important element of novelty regarding the definition of quality concerns the identification of the context in which the company operates. Context of the organization is analyzed considering both the internal and external issues that can impact strategic objectives and the planning of the QMS. In facts, clause 4 of ISO 9001:2015 mentions how the organization needs to evaluate itself and the various elements that influence its context, such the company’s culture, objectives and goals, complexity of products, flow of processes and information, size of the organization, customers, markets, etc.
Internal context can include its approach to governance, its contractual relationships with customers, and its interested parties. In order to determine the external context, a more in depth analysis on social, technological, ethical, political, legal, and economic environment is required. Examples of external context can include:
Government regulations and changes in the law
Economic shifts in the organization’s market
Level of competition
Events that may affect corporate reputation
Changes in technology
The benefits in pills:
The new version ISO 9001:2015 brings the user a number of benefits. Among the others:
A more relevant emphasis on leadership engagement
Support in terms of addressing organizational risks and opportunities within companies
Cross and multidisciplinary structure and language, useful in order to make use of multiple management systems (business continuity, environment, health & safety, social responsibility)
A deeper insight on supply chain management’s efficiency
Thought with a user-friendly approach in the service design
See more info about the Stopson Italiana’s certifications here.
Another great year has passed re-confirming a growth trend for Stopson Italiana.
A slight recovery in oil price and general market demand is boosting our expectations for a brighter future ahead of us.
2017 has been a year of large investments for us in order to set up our Company for future growth: the acquisition of new calculation tools expanding our in-house capabilities to engineer complex projects, the implementation of technical documentation management system to support our ability and responsiveness to deal with most demanding Customers and project specs, the launch of SAP B1 ERP system scheduled for January 2018 are just a few examples of our enlarged platform to address next challenges.
Stopson Italiana remains grateful to all of our Customers who made that possible with their continuous support and trust and wishes you and your family a Merry Christmas and a prosperous 2018!
Our Inlet Duct and Engine Exhaust Silencers will equip a five MAN 16V 32/40 8000 KW Generators on the TCG Anadolu.
The project entails no. 5 Inlet Duct and no. 5 Engine Exhaust silencers both capable to handle 100.600 m3/h flow while achieving 35 dB(A) noise reduction.
The inlet SVR model silencers are made of galvanized steel splitter panels inserted into a painted carbon steel frame with circular inlets and outlets.
The exhaust silencers are made of AISI316 and derived from the Engine Exhaust SM40 DN1200 model with the addition of Spark Arrestors section to prevent the emission of flammable debris from combustion sources.
Stopson Italiana’s R&D team did a great job in assessing all customer requirements and delivering a fully customized solution, thus confirming our capability to leverage our wide range of standard design products optimized around project specifications.
Developed in Stopson Italiana Research and Development lab, these silencers have been field-tested on numerous industrial applications. They are principally conceived to be installed on diesel and gas engines, or on industrial low/middle power gas turbines.
These silencers are based on a absorption and/or resonance sound wave attenuation principle. Depending on the required attenuation performance, 5 models can be chosen: SM 15, SM 25, SM 30, SM 40, SM 50. The nomenclature represents also the nominal diameter of the inlet (e.g. SM15 ND 100, SM25 ND 200, etc).
In addition to Spark Arrestor (here above mentioned), some other optional features can be provided:
Seals and bolts
Supports for vertical and horizontal installation
Stainless steel or other special materials
Highly resistant absorptive material for temperatures over 530° C
The selection of the inlet filtration system is an important stage as poor quality inlet air can significantly impact the operation, performance, and life of the engine, either gas turbine or diesel/gas engine.
In facts, marine vessels need to work even in adverse conditions, thus the continuous operation is often more important than the health of the engine itself. Multiple gas turbines are used on the ships, so there is a spare if one needs to be shut down for maintenance. That can happen in case the filter is clogged, damaged, or blocked, causing – as a consequence – excessive pressure loss.
Moreover, inlet filter housings on marine vessels must be ice and corrosion resistant, due to the significant presence of salt.
Generally, when we refer to a gas turbine intake, some of the consequences of poor inlet filtration entail erosion, fouling and corrosion.
In order to minimize degradation, the metal components of the system needs to be constructed out of a stainless steel or aluminum with adequate corrosion resistant properties. Once a suitable filter system has been selected, a range of ductwork and filtration silencers is provided in order to reduce the noise of fast flowing air into the inlet manifold before reaching the compressor.
These silencers are typically of a ‘splitter type‘ configuration, to minimize pressure drop and increase the airflow into the compressor chamber.
The supply can regard even a standalone filter packages, including pulse filters for removing dust at the inlet of gas turbine packages.
Completed delivery of 12+8 combined Ventilation System Building for Gas storage plant in Sergnano and Minerbio (Italy)
Stopson has successfully fulfilled the delivery of 12+8 Ventilation System Buildings for the natural gas Compression Stations in Sergnano and Minerbio (Italy).
The supply service entails a total of twenty ventilation systems, composed by 20 filtered-and-silencedInlet Systemtogether with the same number of Soundproofed Outlet Systems with forced extraction and fireproof dumpers.
The acoustic warranty covers a noise level reduction of 30 dB(A) SPL at 1mt.The order has been completed and tested phase in these past days.
In general, the plant consists of implementation of 3 turbo-compressor to be set within the Sergnano gas infrastructure. The operations necessary for the installation of the station will be completed as a whole by mid 2018.
The total investment amount is 0.6 bln € (between 2017-2021), aimed to increase the general safety and flexibility of the area, bringing a resources’ capacity increment of 7% circa.
Thanks to a 50 years of experience in the field of industrial soundproofing, Stopson’ technical department is able to deeply analyze and propose the rightest solutions to control noise produced by the extraction systems.
The main solutions consists of rectangular or circular silencers, designed taking into account of the different noise sources and sound spectrum. The installation can be made along the piping or chimneys of emission into the atmosphere.
They can be designed and produced in standard dimensions, or in any size on request and are equipped for external air intake, in addition to return from the filter system.
How to limit the noise propagation (not only in Oil and Gas). Risks and countermeasures of a phenomenon as important as universally underrated.
The noise pollution’s matter has become a well-documented public domain anthology by now.
The World Health Organisation has reported that 40% of Europe’s population is exposed to noise levels in excess of 55dB. Moreover, noise pollution is ranked as second to air pollution, in terms of affecting our health and wellbeing, including diabetes, tinnitus and risk of heart disease.
Noise pollution in Oil and Gas
According to recent study achieved by PSE Healthy Energy and West Virginia University, some modern Oil and Gas techniques – such hydraulic fracturing (or “fracking”) – produce noise that may increase adverse effects on human health.
Fracking can create noise at levels high enough to harm the health of people living nearby (source phys.org). “Oil and gas operations produce a complex symphony of noise types, including intermittent and continuous sounds and varying intensities,” argued PSE Healthy Energy Executive Director Seth Shonkoff.
A adequate set of policies should be specified, in order to safeguard residents and communities, such particularly vulnerable populations (e.g. schools and hospitals). Noise mitigation techniques like perimeter sound walls, noise barriers and acoustic enclosures could represent the most appropriate solutions to hold back this phenomenon.
Noise impact on marine species
This is not all. A recent study led by International Fund for Animal Welfare, reveals the damaging impact of Oil
and Gas noise pollution on whales and dolphins. In the report, they put in evidence how new technologies should reduce their impact on marine environment during the exploration phase (source: International Fund for Animal Welfare).
Noise and Diseases
Numerous epidemiological studies have linked noise to adverse health outcomes too. They include diabetes, depression, birth complications and cognitive impairment in children.
In facts, apart from damage to hearing, exposure to excessive and constant noise can cause other health problems including:
Sleep and heart disease
Elevated blood pressure
Increased susceptibility to colds and other minor infections
Noise in Europe: limits and human tolerance
As we know, the loudness of noise is measured in decibels. Sensitivity to noise differs from one individual to the next, but experts believe that damage to hearing occurs when noise levels are higher than 85 decibels, which is about the loudness of heavy traffic.
Every year, 7 million people in Europe die from heart disease, that would put the toll from exposure to noise at around 210,000 deaths. In England heart disease kills 110,000 people annually, so the deaths linked to noise could be around 3,300.
2% of Europeans suffer severely disturbed sleep because of noise pollution. The researchers calculate that chronic exposure to loud traffic noise causes three per cent of all cases of tinnitus, in which sufferers hear constant noise. Length of exposure is important too. In facts, it is not recommendable to listen to noises of 109 decibels for any longer than two minutes in row.
Noise and public health in U.S.
In US the noise phenomena has been studied deeply, causing a direct response by public health. The Health Impacts Project (HIP) provides since 2013 guidance for policy makers to identify the health consequences of potential projects by making public a national sample of health impact assessment.
Exposure Limits in U.S.
The U.S. EPA recommends an average 24-hr exposure limit of 55 A-weighted decibels (dBA) to protect the public from all adverse effects on health and welfare in residential areas. This limit is a day–night 24-hr average noise level (LDN), with a 10-dBA penalty applied to nighttime levels between 2200 and 0700 hours to account for sleep disruption and no penalty applied to daytime levels.
More info about the Noise sources and Soundproofing solutions in industrial sector can be found here.