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100 Liters of Petroleum, from fuel to petrochemicals

Petroleum, a finite and precious resource, holds within its depths a treasure trove of products that have revolutionized modern society. From fuelling our vehicles to powering industries and shaping everyday objects, petroleum’s versatility is undeniable. However, the extraction, processing, and utilization of petroleum come with significant environmental implications that demand our attention. In this article, we delve into the diverse products obtainable from 100 liters of petroleum and explore their multifaceted impacts on the environment.

Gasoline and Diesel: The Workhorses of Transportation
A substantial portion of 100 liters of petroleum is transformed into gasoline and diesel, the lifeblood of the transportation sector. These fuels power our cars, trucks, and buses, enabling mobility and facilitating commerce. However, their combustion releases harmful pollutants, including carbon monoxide, nitrogen oxides, and particulate matter, contributing to air pollution and respiratory health issues. Additionally, the extraction and transportation of crude oil for gasoline and diesel production can lead to oil spills and habitat destruction, jeopardizing marine ecosystems.

Plastics: Ubiquitous Yet Problematic
A significant volume of petroleum is dedicated to the production of plastics, a ubiquitous material found in countless products, from packaging to clothing and electronics. Plastics have revolutionized various industries due to their durability, versatility, and low cost. However, their environmental footprint is substantial. The production of plastics contributes to greenhouse gas emissions, and their disposal often leads to plastic pollution in landfills, oceans, and waterways. The slow degradation rate of plastics poses a threat to wildlife, marine life, and human health.

Heating Oil: A Winter Necessity
Petroleum is also refined into heating oil, a crucial fuel for homes and businesses in colder climates. It provides warmth during the winter months, but its combustion emits air pollutants, including sulphur dioxide and particulate matter, contributing to smog and acid rain. Furthermore, the extraction, transportation, and storage of heating oil carry the risk of spills and leaks, potentially contaminating soil and water resources.

Lubricants: Ensuring Smooth Operation
A portion of petroleum is used to produce lubricants, essential for reducing friction and wear in engines, machinery, and industrial equipment. Lubricants help extend the lifespan of mechanical components and contribute to efficient operation. However, they can pose environmental risks if not properly disposed of. Improper disposal practices can lead to soil and water contamination, as well as harm to aquatic life.

Asphalt: Paving the Way for Infrastructure
Asphalt, a key component of road construction, is derived from petroleum. It provides a durable and smooth surface for transportation infrastructure, facilitating the movement of people and goods. However, asphalt production and paving release volatile organic compounds (VOCs), which contribute to air pollution and can have adverse effects on human health and the environment.

Gasoline: Approximately 45-50 liters of gasoline can be obtained from 100 liters of petroleum. Gasoline is a primary fuel used in internal combustion engines, powering vehicles such as cars, trucks, and motorcycles.

Diesel: Around 25-30 liters of diesel can be produced from 100 liters of petroleum. Diesel is commonly used in heavy-duty vehicles like trucks, buses, and construction equipment due to its higher energy density and efficiency.

Jet Fuel: Approximately 10-15 liters of jet fuel can be derived from 100 liters of petroleum. Jet fuel is specifically designed for powering aircraft engines, providing the necessary energy and stability for flight.

Heating Oil: About 5-10 liters of heating oil can be obtained from 100 liters of petroleum. Heating oil is commonly used as a fuel source for residential and commercial heating systems, providing warmth during colder months.

Petrochemicals: The remaining 10-15 liters of petroleum can be processed into various petrochemicals, which serve as building blocks for a wide range of products. These petrochemicals include plastics, synthetic fibers, fertilizers, solvents, and pharmaceuticals.

It’s important to note that the exact proportions of these products obtained from 100 liters of petroleum can vary depending on the specific refining process and the desired end products.

Some of them are used to produce several derivatives that are now a part of our daily life, and can be listed as follows:

Ethylene: Production of polyethylene (plastic bags, bottles, films), ethylene oxide (ethylene glycol, antifreeze), and vinyl chloride (PVC).

Propylene: Production of polypropylene (plastic containers, fibers), propylene oxide (polyurethane foams), and acrylic acid (acrylic fibers).

Butylene: Production of butyl rubber (tires, inner tubes), and isobutylene (methyl tert-butyl ether, a gasoline additive).

Benzene: Production of styrene (polystyrene, plastic cups, disposable plates), cumene (phenol, acetone), and cyclohexane (nylon).

Toluene: Production of benzene, toluene diisocyanate (TDI, polyurethane foams), and toluene-2,4-diamine (TDA, aramid fibers).

Xylene: Production of polyester fibers, polyethylene terephthalate (PET, plastic bottles, films), and dimethyl terephthalate (DMT, a precursor to PET).

Refinery Gas: Fuel for cooking, heating, and industrial processes.

Naphtha: Feedstock for steam crackers to produce ethylene, propylene, and other petrochemicals.

Kerosene: Fuel for jet engines, lamps, and heating.

Diesel: Fuel for trucks, buses, and other heavy-duty vehicles.

Fuel Oil: Fuel for ships, boilers, and industrial furnaces.

Lubricants: Reduce friction and wear in engines, gears, and other moving parts.

Asphalt: Paving roads, roofing materials, and waterproofing.

Petrochemical Feedstocks: Raw materials to produce plastics, synthetic fibres, and other petrochemical products.

From the point of view of energy consumption the amount of kWh needed to produce 100 liters of gasoline from petroleum can vary depending on the specific process and technology used. However, a rough estimate can be provided based on typical industry practices.

Crude Oil Distillation: The first step in gasoline production is the distillation of crude oil. This process involves heating the crude oil to a high temperature and separating it into various fractions, including gasoline, diesel, and other products. The amount of energy required for distillation depends on the size and efficiency of the distillation unit, but it typically ranges from 0.1 to 0.3 kWh per liter of crude oil.

Gasoline Blending: After distillation, the gasoline fraction is blended with various additives to improve its performance and meet specific quality standards. This blending process typically requires minimal energy, usually less than 0.01 kWh per liter of gasoline.

Reforming: To increase the octane number and improve the quality of gasoline, it often undergoes a reforming process. Reforming involves converting low-octane components into high-octane ones through chemical reactions. The energy required for reforming can vary depending on the severity of the process, but it typically ranges from 0.2 to 0.5 kWh per liter of gasoline.

Other Processes: In addition to the above steps, gasoline production may involve other processes such as desulfurization, isomerization, and alkylation. These processes aim to remove impurities, improve octane number, and optimize the overall quality of gasoline. The energy required for these processes can vary, but it is generally lower compared to the main steps mentioned above.

Considering all these factors, a reasonable estimate for the total kWh required to produce 100 liters of gasoline from petroleum is approximately 10 to 20 kWh. This range takes into account the energy needed for crude oil distillation, gasoline blending, reforming, and other typical processes involved in gasoline production. It is important to note that this estimate may vary depending on specific refinery configurations, process efficiencies, and the quality of the crude oil being processed.

Electrical cars are slowly having a place in the daily life of citizens, and the technology progress is helping to achieve or extend autonomy of batteries. On the other hand, endothermic cars still playing an important role in the fuel consumption, but if all the cars in world were electric, there will be a surplus of gasoline/diesel.

It is possible to transform gasoline into petrochemicals ?

Yes, it is possible to transform gasoline into petrochemicals. Petrochemicals are chemical compounds derived from petroleum or natural gas, and gasoline is a refined product of crude oil. The process of converting gasoline into petrochemicals is called reforming.

Reforming is a chemical process that involves heating gasoline in the presence of a catalyst, such as platinum or rhenium. This causes the gasoline molecules to break down and rearrange, forming new molecules that are more useful as petrochemicals. The most common petrochemicals produced by reforming are ethylene, propylene, and benzene.

Ethylene and propylene are used to make plastics, synthetic fibers, and other chemicals. Benzene is used to make plastics, dyes, and detergents.

The reforming process can be used to convert a variety of different types of gasoline into petrochemicals. The type of gasoline used will affect the yield and composition of the petrochemicals produced.

Reforming is an important process in the petrochemical industry. It allows refineries to convert gasoline, which is a relatively low-value product, into more valuable petrochemicals. These petrochemicals are used to make a wide variety of products that we use every day.

Here is a more detailed explanation of the reforming process:

1. The gasoline is heated to a high temperature, typically between 500 and 600 degrees Celsius.
2. The heated gasoline is passed over a catalyst, which is a material that helps to speed up the chemical reaction.
3. The catalyst causes the gasoline molecules to break down and rearrange, forming new molecules.
4. The new molecules are cooled and condensed into a liquid.
5. The liquid is then separated into its individual components, such as ethylene, propylene, and benzene.

The reforming process is a complex one, but it is essential for the production of petrochemicals. Without reforming, we would not be able to make many of the products that we rely on every day.

How many kWh are needed to transform gasoline in petrochemicals?

The amount of kWh needed to transform gasoline into petrochemicals can vary depending on the specific petrochemicals being produced, the efficiency of the conversion process, and the energy source used. However, as a general estimate, it takes approximately 10-12 kWh of electricity to produce 1 kg of petrochemicals from gasoline.

For example, to produce 1 kg of ethylene from gasoline, which is a common petrochemical used to make plastics, it would require approximately 10-12 kWh of electricity. This electricity is used to power the various processes involved in the conversion, such as heating, cooling, and separation.

It’s important to note that the energy required for petrochemical production can also vary depending on the type of gasoline being used. For instance, gasoline with a higher-octane rating may require more energy to convert into petrochemicals compared to gasoline with a lower octane rating.

Additionally, the efficiency of the conversion process plays a significant role in determining the energy consumption. More efficient processes, such as those that utilize advanced technologies or optimize energy usage, can reduce the amount of electricity needed to produce the same amount of petrochemicals.

Overall, the energy consumption for transforming gasoline into petrochemicals is a complex issue that depends on various factors. However, as a rough estimate, it takes approximately 10-12 kWh of electricity to produce 1 kg of petrochemicals from gasoline.


The diverse products obtained from 100 liters of petroleum have indelibly shaped modern society, providing convenience, mobility, and numerous essential goods. However, their production and use come with significant environmental consequences.

If not needed for fuel, petroleum is needed as raw material to produce several products that are essential for our daily life, directly or indirectly. Transition from endothermic to electric car of course plays an important role in reducing CO2 emission, but at the same time this create a surplus in gasoline that should be than transformed to petrochemicals. This excess should be considered when considering energy transition.

Navigating the Levelized Cost of Energy (LCOE) Landscape in Renewable Energy

The global energy transition towards renewable sources has accelerated in recent years, driven by environmental concerns and technological advancements. As renewable energy technologies mature, their cost-competitiveness has become a crucial factor in their widespread adoption. The levelized cost of energy (LCOE) is a widely used metric to assess the economic viability of electricity generation technologies. It represents the average cost of producing one megawatt-hour (MWh) of electricity over the lifetime of a power plant.

Decoding the LCOE Formula

The LCOE calculation utilizes a straightforward formula:

LCOE = (Total Project Cost + Operating and Maintenance (O&M) Costs) / Energy Output


  • Total Project Cost encompasses the initial capital expenditure (CAPEX) for equipment, installation, and development.
  • O&M Costs represent the ongoing annual expenses for maintenance, repairs, monitoring, and land lease payments.
  • Energy Output refers to the total electricity generation over the lifetime of the power plant.

Understanding the Influences on LCOE

Several factors can significantly impact the LCOE of renewable energy technologies:

  1. Technology Advancements: Technological advancements, such as efficiency improvements and cost reductions, directly translate to lower LCOE.
  2. Site Selection: The quality of renewable energy resources, proximity to transmission lines, and land availability influence the CAPEX and overall LCOE.
  3. Government Incentives: Financial support from government subsidies, tax breaks, or feed-in tariffs can lower financing costs and reduce LCOE.
  4. Project Scale: Larger renewable energy projects often benefit from economies of scale, leading to lower LCOE per MWh.
  5. Operational Efficiency: Efficient operations and maintenance practices can optimize plant performance and reduce LCOE.

Comparing LCOE across Renewable Energy Sources

The LCOE of renewable energy sources has undergone significant decline in recent years, making them increasingly competitive with fossil fuel-based alternatives. Here’s a comparative overview of LCOE for various renewable energy technologies:

TechnologyLCOE (USD/MWh)
Onshore Wind (2023)$25-40
Offshore Wind (2023)$40-60
Solar Photovoltaic (2023)$30-50
Concentrated Solar Power (2023)$50-100
Geothermal (2023)$40-100
Hydropower (203)$20-40

As technology continues to advance and costs decrease, the LCOE of renewable energy technologies is projected to further decline, making them even more cost-effective and attractive options for electricity generation worldwide.

Books and Sources for Further Exploration

  1. “Renewable Energy Engineering: Power for a Sustainable Future” by Dennis L. Wendell
  2. “Renewable Energy: Engineering, Technology, and Science” by John D. Stein
  3. “The Future of Energy” by Fatih Birol
  4. International Renewable Energy Agency (IRENA)” website: https://www.irena.org/: https://www.irena.org/
  5. “Renewable Energy Policy Network for the 21st Century (REN21)” website: https://www.ren21.net/: https://www.ren21.net/

Future Trends Shaping the LCOE Landscape

The future of LCOE in renewable energy is promising, with several trends expected to further reduce costs and drive widespread adoption:

  1. Accelerated Technological Advancements: Ongoing technological advancements, such as higher efficiency modules and improved turbine designs, are expected to significantly reduce the cost of renewable energy generation.
  2. Economies of Scale: As the production of renewable energy technologies increases, economies of scale will drive down costs, making them even more competitive.
  3. Government Policy Support: Continued government support through subsidies, tax breaks, and renewable energy targets will further incentivize investment and reduce the cost of renewable energy.
  4. Optimizing Operations and Maintenance: Implementing efficient operations and maintenance practices will help maintain high performance and reduce ongoing costs, further lowering LCOE.
  5. Market Maturation: As the market for renewable energy matures, competition will increase, leading to further cost reductions and increased innovation.


The LCOE is a crucial metric for assessing the economic viability and competitiveness of renewable energy technologies. As

Hydrogen Generation Due to High Voltage in Cathodic Protection


Cathodic protection is a widely used technique to prevent corrosion of metal structures in various industrial applications. The process involves making the metal structure cathodic with respect to a more easily corroded metal or an inert anode. This results in a flow of current, which causes the metal to be protected from corrosion. However, cathodic protection can also lead to the generation of hydrogen gas, which can cause hydrogen embrittlement.

Technical Background

When cathodic protection is applied, a voltage is applied to the metal structure, which is more negative than the equilibrium potential of the metal in the electrolyte. This negative potential causes a flow of electrons from the anode to the cathode. At the cathode, hydrogen ions are reduced to form hydrogen gas. This is a normal process in cathodic protection, but at high potentials, the amount of hydrogen generated can be excessive and lead to hydrogen embrittlement.

Hydrogen embrittlement occurs when hydrogen diffuses into the metal and interacts with the metal lattice. This can reduce the ductility and fracture toughness of the metal, making it more susceptible to cracking and failure. The severity of hydrogen embrittlement depends on factors such as the material, the level of hydrogen exposure, and the applied stress.


Hydrogen embrittlement was first observed in the mid-19th century in steel rails used in railway tracks. The rails were observed to fracture suddenly, even though they had not been subjected to excessive loads. It was later discovered that the rails had been exposed to hydrogen gas, which had caused them to become brittle and prone to fracture. Since then, hydrogen embrittlement has been observed in various other metals and alloys.

Mitigation Strategies

To mitigate the risk of hydrogen embrittlement in cathodic protection, several strategies can be employed. One approach is to limit the amount of hydrogen generated at the cathode by using lower cathodic potentials or adding inhibitors to the electrolyte. Another approach is to use materials that are less susceptible to hydrogen embrittlement, such as high-strength alloys or titanium.

Post-processing techniques can also be used to remove or reduce the amount of hydrogen in the material. For example, annealing or heat treatment can be used to diffuse the hydrogen out of the metal. Additionally, hydrogen diffusion barriers can be applied to prevent hydrogen from entering the metal in the first place.


In conclusion, cathodic protection is an effective method to prevent corrosion of metal structures, but it can also lead to the generation of hydrogen gas and subsequent hydrogen embrittlement. To mitigate the risk of hydrogen embrittlement, it is important to limit the amount of hydrogen generated at the cathode and use materials that are less susceptible to hydrogen embrittlement. Regular inspections and proactive corrosion management are crucial to detecting any signs of hydrogen embrittlement or other types of corrosion damage.


  • H. Wang, J. Zheng, Q. Zhang, & Y. Wei. (2019). Mitigation of hydrogen embrittlement of a 7B04 aluminum alloy by controlling the microstructure. Materials & Design, 170, 107675.
  • M. W. Kendig & R. G. Buchheit. (2003). Hydrogen embrittlement. Corrosion: Understanding the Basics, 305-324.
  • J. R. Scully & H. Zhu. (2010). Hydrogen embrittlement and hydrogen-induced cracking. ASM Handbook, 13B, 1085-1101.

Hydrogen from Ammonia, a fuel for the future

Green ammonia is an emerging technology that has the potential to revolutionize the production of hydrogen and significantly reduce carbon emissions. In this article, we will discuss the production of hydrogen from green ammonia, key production and money figures, companies involved, and future trends.

Production of Hydrogen from Green Ammonia

Green ammonia is produced by using renewable energy sources such as wind or solar power to power the Haber-Bosch process, which produces ammonia. Green ammonia can then be used as a feedstock for the production of hydrogen through the process of ammonia cracking. The reaction is endothermic, requiring a reactor heated to a high temperature of around 700-900°C to break down ammonia into its constituent elements, nitrogen and hydrogen.

Key Production and Money Figures

The production of hydrogen from green ammonia has several advantages over traditional methods, including zero carbon emissions and lower energy requirements. According to the International Energy Agency (IEA), the production of green ammonia is expected to reach 25 million tonnes by 2030 and 500 million tonnes by 2050. The IEA also estimates that the production of green ammonia could reduce the cost of producing hydrogen by up to 50% compared to traditional methods.

Companies Involved

Several companies are involved in the production of green ammonia, including Yara, the world’s largest producer of ammonia, and Siemens Energy, which has developed an electrolysis-based process for producing green ammonia. Other companies involved in the production of green ammonia include Ørsted, a leading renewable energy company, and Air Liquide, a global leader in industrial gases.

Future Trends

The future of green ammonia production looks bright, with the potential for significant growth and contribution to reducing carbon emissions in the energy and agricultural sectors. The IEA has identified green ammonia as a key technology that could help to reduce carbon emissions. Green ammonia has the added benefit of being used as a fertilizer, further reducing the carbon footprint of agriculture. In addition, the use of green ammonia in the shipping industry as a fuel is being explored as a potential replacement for fossil fuels.


Green ammonia is a promising technology that has the potential to revolutionize the production of hydrogen and significantly reduce carbon emissions. Key production and money figures suggest that the production of green ammonia could increase significantly over the next few decades, with the potential to reduce the cost of producing hydrogen by up to 50%. Several companies are involved in the production of green ammonia, and the future looks bright with the potential for significant growth and contribution to reducing carbon emissions in the energy and agricultural sectors.

Do you like vibrations? Have fun!

Fourier wave generator

Wave generation concept & theory is the key to understand vibrations in industry with a consequence on maintenance.

Discrete: Allows you to create a wave choosing the armonics value. turn on the speaker to hear it!

Wave Game: Try to match the wave below by chosing armonics values. there are 5 levels, level 1 with one armonic, level 5 with 5+ harmonics

Wave Packet: A full in depth view of fourier wave generation

Waves on a string

With this game you can study the effects of resonance, wave fundamentals and damping. Try to play around with frequency, amplitude, damping and tension.

Have fun!

Compressor Inspection in Switzerland

Compressor and pumps are two rotating equipments that carry fluids inside a plant or circuit.

Two of the most common compressor used in industry are centrifugal and reciprocating, depending on the duty they are involved. Also axial compressor and screw are used in some applications.

For testing, exists two reference standards API 617 for centrifugal compressors and API 618 for reciprocating compressors. In both documents there is a dedicated section for inspection requirements, but the client can decide the extention of the inspecting activities.

We as a company have a vast experience with inspecting compressors, both centrifugal and reciprocating whose have some activities in common and some specific for their category. Starting from the very beginning of the construction phase, we assisted hydrostatic pressure test of the casing, that can house the cylinder in case of reciprocating compressor or the impellers in case of centrifugal compressor.

Centrifugal Compressor

Successively overspeed and balancing of the impeller is key step in ensuring compressor performance. Assisting to this step is very important because allows to verify the fundamental frequency of the impeller which is important for maintenance and performance analysis.

After balancing, performance and running test are performed. Performance test scope is to simulate process condition at supplier shop and determine the behaviour in terms of polytropic head and thermodynamic efficiency. To achieve this, there is a sequence of steps to follow in order to get the nearest result of the behaviour compressor can have under process condition.

On the other side, running test scope is to determine reliability/endurance behaviour of the compressor. After completion of both performance and running test, inspection of the bearings is done to verify wearing, scratches that are caused by tests.

Final stage is assembly and final inspection.

Being based in Switzerland, we have the assignment to witness tests from the first step to the final stage, packing

Reciprocating compressor

Reciprocating compressor inspection, starts with hydrostatic test of the casing that will house the cylinders. After hydrostatic, air & helium test are done to fully determine possible leaks.

Performance test is a key step for evaluate compressor behaviour and also cylinder head inspection is needed. In contrast with centrifugal compressor, after running test, piston allignment need to be measured and verify if in tolerance.

Packing is the last activity to do by checking tools and spare parts provision.

Hinkley Point C – Blade construction Inspection

Hinkley Point C nuclear power station (HPC) is a project to construct a 3,200 MWe nuclear power station with two EPR reactors in Somerset, England.

The site was one of eight announced by the British government in 2010 and in November 2012 a nuclear site licence was granted.

Power generation is made by two GE Arabelle nuclear steam turbine. One of the most important components in power generation by turbine is the shape of the blade.

As based a company based in switzerland, we were chosen to follow construction of blade of the 1st stage of the turbine by witnessing forming, welding, NDE and dimensional check.

Finished blades

Blades (airfoils) were made in Switzerland by a Swiss manufacturer specialized in airfoil construction for different applications, ranging from energy production to aviation.

Airfoil is made by shaping two plates, one for high pressure side and another for lower pressure side. After forming, the two halves are welded at the leading edge and trailing edge.

Finally after machining airfoil get his final shape and can be inspected for weld defects, geometrical deviations and surface condition.

Sellafield project – Weld Supervising

After 2 interviews with Sellafield representative our company was involved as Tier 5 on full time basis in supervising weld activities, NDE & FAT testing 5 gate valves intended for HVAC system lifetime operational. The valves were fabricated in Switzerland, Basel area.

Sellafield, located 500 km north London, is the biggest nuclear site in Europe. Covering 265 hectares, comprises 200 nuclear facilities, 1000 buildings and 10.000 employees.

Starting from 2003, nuclear production of power generation was shut down leaving operative facilities for reprocessing or storage of spent nuclear fuel and/or nuclear waste coming from Europe.

The site is due to be fully decommissioned in 2120.

The Project

The Box Encapsulation Plant Delivery Team is an unincorporated joint venture of Amec Foster Wheeler, Balfour Beatty and Jacobs.

The framework contract for the project was awarded in October 2014 and is being delivered as an integral part of the Magnox Swarf Storage Silo (MSSS) programme for Sellafield Ltd, which is tackling the clean-up of one of the most hazardous legacy facilities on the Sellafield site.

When complete BEP will deliver the capability to treat nuclear waste recovered from MSSS, immobilise it and prepare it for storage. In addition, the BEP may also process waste recovered during the decommissioning of other Sellafield facilities including the First Generation Magnox Storage Pond (FGMSP) and the Pile Fuel Storage Pond (PFSP).


After 2 interviews with Sellafield representative our company was involved on full time basis in supervising welding activities, NDE & FAT testing 5 gate valves intended for HVAC system lifetime operational. The valves were fabricated in Switzerland, Basel area.

According to Nuclear QA grading, the valves (or dampers) were classified with a quality grade 2:

Failure is likely to lead to a MAJOR but less serious radiological risk


cause serious injury to persons


lead to a breach of the Site Licence or Environmental or Statutory requirements


lead to SIGNIFICANT cost penalty


The construction of the valve isin 304L, 5 mm plate with metal-to-metal sealing and removable internal mechanic blade.

Welding process was divided in 3 stages to avoid deformation due to high precision required to ensure -0.5 mbar vacuum.

The first stage isthe fit-up; the second stage consist in more than 300 welds seams with different lengths, third stage only minor welds.

The welding process was manual TIG or GTAW with only one approved weld position, having an impact on the handling of the damper with final weight of 350 kg. One of the key parts of welding was the colour of the weld and the grade of inerting/shielding.

First weld layer was monitored in terms of forming gas flow rate, weld seam length (max. 100 mm) and welding parameters. Since back gouging was not practical due to low space, the entire body was sealed and inerted with forming gas. An oximeter was used for monitoring the quantity of oxygen generated during welding.

Surface wet pickling was not practicable due to impossibility to ensure water full dryness so the final surface condition was glassblasted (100 microns glass microsphere). A test was done the verify the removal power of the glass against weld seam colour. It was found that the colour of the welds where the O2 was above 30 ppm, cannot be removed.

After 200 working days all 5 valves were completely welded.

Before testing, cleaning was achieved with solvent; the chemical composition of the pure inlet solvent stream was monitored and compared with the outlet wasted stream. When the difference between clean inlet & outlet contaminants was zero, the damper was considered fully clean.

Testing was aimed to check vacuum tightness with obtained values of zero flow rate passing to the seats.