Ensuring the Structural Integrity of Reactor Vessels for Safety

Reactor vessels are the protective containment surrounding the nuclear fission core in a nuclear reactor. The vessel which is the central component of the reactor coolant system has a cylindrical shell with a spherical bottom head and a ring flange at the top. A closure head is bolted to the flange. It is typical for the reactor vessels to be made with stainless steel usually of the ferritic type that is well suited for welding and with the high strength and toughness but low porosity under neutron irradiation. When the reactor is operated, neutron radiation from the reactor core causes embrittlement of the reactor pressure vessel materials making it less tough and less capable of maintaining its structural integrity.

Reducing the rates of embrittlement in reactor vessels

  • Pressurized water reactors (PWRs) are considered to be more susceptible to embrittlement than the boiling water reactors (BWRs) since the BWR vessels generally experience less neutron irradiation and therefore less embrittlement. Many utilities make use of core designs that will reduce the number of neutrons that will reach the vessel wall and will minimize the rate of embrittlement on the reactor vessels.
  • Another factor that contributes to a certain extent towards the embrittlement of the reactor vessels is the kind of steel used. Steels with a higher proportion of copper and nickel tend to be more susceptible to embrittlement than steels with a lower proportion of the 2 elements. 
  • Another reason for PWR reactor vessels embrittlement is pressurized thermal shock that can occur under some accidents scenarios when cold water is introduced to the reactor vessel while it is still pressurized. The introduction of cold water can cause the vessel to cool rapidly resulting in large thermal stresses to steel. These thermal stresses along with the high internal pressure and an embrittled reactor vessel could lead to cracking that will ultimately lead to failure of the vessel. This can be a potential safety issue which is the focus of inspections on the reactor vessel structural integrity.

Metallurgy and fabrication of stainless steel reactor vessels

  • Reactor vessels for light water cooled reactors are usually manufactured from low carbon alloy steel to secure strength. The reactor pressure vessel is the most critical pressure-boundary component as far as safety and plant life is concerned which requires that the material for pressure retaining component should have sufficient strength and fracture toughness for the assurance of structural integrity.
  • The reactor vessels are typically lined with stainless steel for corrosion prevention against water when used as a reactor coolant. Stainless steel contains sufficient amounts of chromium to form a passive film of chromium oxide that prevents surface corrosion by blocking oxygen diffusion into the steel surface and blocks corrosion from spreading into the internal structure of the reactor vessel.
  • The manufacture of reactor vessels is difficult, time consuming and expensive due to the absolute necessity of near perfection in forming, welding and machining. Parts are forged, heat treated, quenched and tempered before they are subjected to ultrasonic inspection, tangible tensile tests, impact tests, bend tests and finally magnetic particle inspection.
By valariearthur

NH3 Monitoring: For a Safe Working Environment

What is NH3 and NH3 Monitoring?

NH3, otherwise known as Ammonia, is a colorless and hazardous gas which is characterized by its pungent odor. It is generally considered an irritant in many industrial work places; and they are considered toxic if they exist at very high levels. They are also likely to irritate the respiratory system. Ammonia is often utilized in cleaning products, fertilizers and pharmaceuticals. There are certain industrial applications that can result to risky levels of Ammonia.

 Manufacturing and industrial plants must include ammonia monitoring as part of their safety and health standards. These industries can very well benefit from NH3 monitoring with the use of Ammonia gas detectors:

–        Manufacturers of NH3 or Ammonia

–        Manufacturing facilities that utilize cleansing products with ammonia content

–        Meat packing facilities

–        Refrigeration facilities like ice cream or food processing plants

–        Manufacturers of fertilizers

–        Manufacturers of pharmaceutical and cosmetic products

–        Textile Mills

The Dangers of Ammonia Leaks

Ammonia is a common gas element that’s found in production facilities. What a lot of people may not realize is that it is also among those common gases that are very dangerous. It is a toxic gas that’s composed of nitrogen and hydrogen; once exposed to high levels of this gas, one can suffer serious health issues. In addition, once a leak in a highly enclosed area happens, there is a danger that ammonia could mix with other chemicals and lead to highly toxic or explosive gas leak.

–        Short Exposure can result to:

Burning sensation in the eyes, nose, and throat


Choking fits

–        Long Term Exposure can result to:

Severe irritation

Chemical burns to the skin lungs, and eyes

Permanent scarring


The possibility of ammonia leak is always likely to happen in so many industrial applications; as such, leak detection systems should be given high consideration. The best way prepare for a leak situation and to prevent its serious repercussions is to be prepared and to install reliable NH3 monitoring system.

By valariearthur

Ammonia Monitoring for a more Sustainable Environment

Chloramine is a popular disinfectant that’s often utilized in water purification. Mixing ammonia (nh3) to water with chlorine content produces chloramines. However, water treated with chloramines can be a breeding ground for bacteria because of its ammonia content. Nh3 analyzer is utilized to help monitor the operation of ammonia in treated water.

The value of Nh3 Analyzer in water purification and treatment facilities

When there’s excessive ammonia in treated water, nitrates may form as by-products. Their presence in the water distribution system will create the need to reduce the quantity of ammonia. Free chlorine residual might do the job, but the quantity has to be thoroughly controlled to avoid issues on the taste and odor of the water. Efficient nh3 analyzer can constantly monitor the plant facility to ensure that the presence of ammonia in the treated water is kept at the appropriate levels. Samples can be acquired from the main outflow of the water purification plant.

Ammonia monitoring for a safer and healthier environment

More and more efforts are being exerted to minimize the toxic effects of pollutants both to humans and the environment. These are evidenced by the number of legislations and environmental regulations that are being imposed and implemented all across the globe. Gas detectors in multiple designs and features are being introduced so that industries can properly comply with such legislations. 

In a natural environment, the concentration of ammonia may not be at the critical level; however, in certain locations like farming areas, the need to have reliable nh3 analyzers becomes of primary concern. Aside from helping in the early detection of ambient ammonia levels, modern monitoring devices are being utilized to obtain better understanding of ammonia and its other impacts in the environment.

In a nitrogen-controlled environment, the presence of ammonia gas and ammonium ions can actually enhance the growth of plants and essential crops. However, without proper monitoring, the same nutrients can be detrimental to these plant communities. Ammonium ion deposits on the soil increase acidity of the soil, resulting to release of hydrogen ions and conversion of ammonium to nitrate.

An nh3 analyzer serves as point of reference when it comes to meeting air quality standards. They can detect ammonia and every industry is encouraged to do their share in utilizing one so that the objective of maintaining cleaner air is achieved.

By valariearthur

How CO2 Analyzer Works

Carbon Dioxide is the number one culprit in the ever-growing concerns about global warming. It comes from the fossil fuels such as gas, oil and coals which then spread into the air and into the atmosphere and eventually cause the destruction of the ozone layer.

Today, as the industries are rapidly growing, so does the effect of global warming. Since there is massive emission of CO2, the demand to regulate it is now a global campaign. In fact, nations have entered into agreements that urge industries in their respective countries to minimize emission of carbon dioxide and minimize its ill-effects.

In order to scientifically evaluate the amount of carbon dioxide produced in various industries, instrumentations have been developed. Carbon dioxide analyzers or CO2 analyzers are devices designed to detect and quantify the amount of carbon dioxide. CO2 analyzers are mainly used in food and beverage industries, chemical laboratories, medical laboratories, and pharmaceutical industries.

It comes in a variety of sizes and range of detection. CO2 analyzers have different capacities. There are those that can detect other gases like sulfur dioxide and oxygen other than carbon dioxide.

Industries have a wide variety of options given that most CO2 analyzers have been incorporated with the latest technology and specification requirements for ease of use. Others have improved readings so that they will be more accurate.

This instrument is very essential in monitoring and regulating CO2 emission especially in major industries. It provides more or less a total picture of the amount produced inside factories. This is also part of the corporate social responsibilities of various business entities.

Businesses must not only care for profit but also for the environmental damages brought about by their use of fossil fuels. This way, the environment would be sustainable and provide a condition that is conducive for their business to further prosper.


By valariearthur

Considering all Pertinent Factors in the Choice for High Pressure Pumps

A lot of different machineries and equipment are used in industries and not all of them can be considered durable. Constantly having to replace equipment can be detrimental to a plant as it will certainly cause downtime not to mention the cost of repairs and replacement. When using high pressure pumps, it is essential to maintain proper pressure and durability so that the job will be completed within the allotted time. Pumps play a big role in process industries since no plant can be operated successfully without the reliable high pressure pumps that will handle liquid to and fro various vessels, storage tanks, heights and lengths during the process of operations.

Common types of high pressure pumps

  • Internal and external gear pumps – the basic gear pump has two main types, the external gear pump which use two external gears and the internal gear pump that use both internal and external gear. In the external gear pump, the mechanism is usually driven by one of the toothed gears which in turn drive the other. In the internal gear pump, only one drive gear is required for the mechanism to function but it is also possible to use both.
  • Lobe pumps – used in a variety of industries because they offer superb sanitary qualities, high efficiency, reliability, corrosion resistance and good clean-in-place (CIP) and steam-in-place (SIP) characteristics. Lobe pumps are similar to the external gear pumps in operation but the lobes do not make contact because it is prevented by external timing gears in the gearbox.
  • Vane pumps – is a hydraulic pump that uses a series of flat protrusions that rotate to trap and move liquid through the hydraulic system. Vane pumps are considered efficient for high speed operations. They also produce high pressure discharges and are ideal for thin liquids.

Critical points in the selection of pumps

  • Fluid characteristics – this is usually the most important factor in the selection of pumps whether for the dynamic (kinetic) pumps or high pressure pumps (positive-displacement pumps). Fluid characteristics should be considered as to the chemical identity of the fluid pumped, PH, dissolved oxygen, corrosive or abrasive nature, concentration, suspended solids and temperature.
  • Absolute viscosity – power requirements increases with liquid viscosity. The higher the viscosity, the greater the head loss due to friction in the pipeline and pump casing as well as the whole system.
  • Specific gravity – can impact on pump life along with its performance
  • Temperature – the operating temperature of the pump can affect overall performance. Pumps can perform efficiently over an approximate temperature of up to 80oC.  When considering temperature, it includes the combined ambient temperature and liquid temperature.
    • Space available for the pump – the model and size of the pump can be influenced by ease of operation and maintenance. The pump can be installed either vertically or horizontally whichever is a more cost effective and efficient arrangement. It is also important to consider whether installation is temporary or permanent to help decide the material of construction as well as the space available.
By valariearthur

Avoiding Corrosion with the Use of Stainless Steel Fittings

Stainless steel fittings are of fundamental importance to many industries due to certain properties of corrosion-resistance and temperature-resistance not to mention its unmatched strength. Stainless steels resistance to corrosion and staining, low maintenance including its familiar luster makes it an ideal material for different applications from coils, tubing, sheets, plates, bars, fittings and wire used in many different instruments and devices. Due to the fact that steel does not oxidize, stainless steel fittings are widely used in commercial kitchens and food processing plants since it can be steam-cleaned and sterilized without the need for surface finishes or paint. Easy cleaning capabilities make them ideal for hygienic areas where washdowns are commonly done.

Features of stainless steel fittings

  • Its properties of self-healing help reduce the penetration of rust/corrosion and eliminate damage to the fitting
  • Stainless steel fittings manage to retain its strength whether in extreme heat or extreme cold temperature conditions
  • Fittings surface is easy to clean and maintain
  • Due to the superior strength and durability of stainless steel fittings, it reduces replacements which lowers the total cost of ownership and increases the returns on investment
  • Stainless steel fittings do not need any surface finishes or paint as well as harsh environment-damaging cleaners to make it look like new
  • Stainless steel fittings are ideal for industrial MRO and OEM applications in the food and beverage industry, pharmaceuticals, petrochemicals, wastewater and other corrosive environments

Classifications of stainless steel

  • Austenitic stainless steel – makes up 70% of total stainless steel production. It contains a maximum of 0.15% carbon, a minimum of 16% chromium and sufficient nickel/manganese to retain its austenitic structure at all temperatures whether extreme cold or extreme heat. The most widely used austenite steel is the 304 which is also known as 18/8 due to its composition of 18% chromium and 8% nickel.
  • Ferritic stainless steel – has reduced corrosion resistance due to lower chromium and nickel content; however, they have better engineering properties than austenitic steel and considered to be less expensive. They contain between 10.5% to 27% chromium and very little nickel.
  • Martensitic steel – not so high corrosion resistance if compared to austenitic and ferrous stainless steel but extremely strong and tough, highly machinable and can be hardened using heat treatment. Martensitic steel contains 12-14% chromium, 0.2-1% molybdenum, less than 2% nickel and about 0.1-1% carbon. Its carbon content makes it harder but a bit more brittle.
  • Duplex stainless steel – a 40/60 combination of both austenitic and ferritic stainless steels to achieve twice the strength of austenitic stainless steel and improved resistance to localized corrosion particularly pitting, crevice corrosion and stress corrosion cracking.
  • Precipitation-hardening martensitic stainless steel – has corrosion resistance comparable to austenitic stainless steel but can be precipitation hardened to reach higher strengths comparable to the martensitic grades.

It is always important to focus a lot of attention on the alloying elements used in stainless steel fittings to avoid corrosion. It is also extremely important to avoid dropping below the minimum chrome threshold so as to guarantee the specific properties of the stainless steel fittings.


By valariearthur

Important Facts You Should Know About Elevator Modernization

Despite the increasing need for elevator modernization, the elevator fixture market has not been able to provide outstanding innovations and significant progress. For years, this market has been somewhat stagnant and unprogressive, as it has not kept up with the times. But luckily, there are a lot of elevator modernization companies that can help you enhance the technology of your elevator.

Elevator modernization, or also referred as lift modernization, refers to the process of upgrading an elevator’s technology and critical parts in order to improve safety and system performance as well as increase its curb appeal. Furthermore, this upgrading process enables the elevator to use new technology and adhere to the city’s current codes and rules about elevator systems.

For the most part, elevator modernization will affect the following parts of the elevator system:

–          Controller equipment, which is a part of the system that controls the elevator’s movement through the floors

–          Hoist motor and machines (the elevator parts that do the heavy lifting on an elevator system)

–          Electrical wiring

–          Electronic cab buttons (control the destination floors, lights, and many more)

–          Door tracks

–          Paneling

–          Elevator phone

–          Cylinder life jacket

–          Emergency lighting and alarm

The importance of modernization

Elevator systems are normally meant to provide 25 to 40 years of service, provided that the periodic inspections and maintenance required the manufacturer are flowed. In some cases, elevators can last up to 50 to a hundred years. As the elevator gets older, the system’s components become less functional, which can greatly affect its performance and safety. Fortunately, elevator modernization can make these components more operational and efficient.   

The perks of lift modernization

There are a lot of benefits that can be offered by this upgrading process. Here are some of the benefits of having your elevator system modernized:

–          Improves the system’s reliability and functionality by replacing its mechanical contacts and relay with solid-state and advanced electronics.

–          The quality of ride may be enhanced by replacing its motor-based design with VVVF (Variable-Voltage, Variable Frequency) drives. In turn, this upgrading process provides seamless deceleration and acceleration in the elevator system.

–          Improved passenger safety by upgrading equipment and systems to adhere to current safety codes

Time to modernize your elevator system

You should consider modernizing your elevator system if any of the following statements are true:

–          People spend a lot of time in waiting for the elevator to come in the lobby

–          The passengers in the elevator complain about ride comfort, poor leveling or unusual noise

–          You are not sure if your elevator has complied with the current safety standards and codes

–          Your elevator has not been upgraded for more than a decade

–          Its locks are out-of-date and worn

–          It shuts down very often

–          Your elevator is always overcrowded

If any of these statements are true, contact a professional elevator company and let them assess the situation. As highly trained specialists, professional elevator companies can help you determine if your elevator system needs to be modernized or upgraded. Moreover, they can provide the best solutions to improve your elevator’s performance, safety and functions.

By valariearthur

Elevator Maintenance and Its Importance

An elevator is indeed a crucial part of any apartment and high-rise construction. With its amazing speed and elevator pushbuttons, this vertical transport system can give you the ability to quickly transverse from one floor to another in a single bound.  As a crucial transport system, it is essential for a building owner to monitor his or her elevator. With proper elevator maintenance, not only are you optimizing your elevator’s performance, but you are also ensuring the safety of your employees or apartment residents.  Moreover, it helps avoid the costly repair bills for your elevator pushbuttons and its other fixtures.

Elevators are complex vertical transportation machines. Hence, there are a lot of parts that have to be maintained regularly to keep it up to the safety codes and standards. Here are some of the parts that have to be maintained within an elevator system:

–          Elevator pushbuttons

–          Gears

–          Doors

–          Main drive system

–          Ropes and safe backup ropes

–          Emergency braking system, including over-speed devices and buffers

–          Hydraulics

–          Overload detection devices

–          Electrical devices like fuses, safety devices, earth bonding and earthing

–          Etc.

Frequency of elevator maintenance

As building owner, it is your responsibility to have your elevator examined at least once in every six months, specifically if your elevator is used to carry animals and people only. But if it carries nothing but load like inanimate objects and industrials, you have it checked every year. Also, if there have been any critical changes in the building or use of the elevator system, make sure to have it inspected by a professional as soon as possible.

There are a few situations, however, in which you need immediate elevator maintenance and repairs, such as

–          Elevator pushbuttons won’t work

–          Elevator doors do not close at all

–          The elevator does not more even will its doors appear to be closed 

Elevator maintenance is something you cannot do on your own. Yes, there are a lot of things that can be handled though DIY manuals and kits, but this is not the case with elevators. As mentioned, elevators are complex and intricate systems that regular consumer cannot comprehend. As such, you need to enlist the services of a licensed elevator repair technician, whenever you are maintaining your elevator.

Not all elevator maintenance providers can deliver quality service. But, you can find a good elevator maintenance specialist through these tips and suggestions:

–          When looking for an elevator specialist, the first thing you have to do is to gather recommendations from the people you know and trust. Keep in mind that word is mouth is still the most reliable way to find quality service.

–          Aside from the people you know, you may also use online sources like social networks and community boards to know the whereabouts of the finest elevator companies in your area.

–          Before you hire an elevator maintenance provider, ask if they are bonded and insured. Also, make sure that they have the right licensed to maintain and repair elevators in your area.

–          Only consider companies and specialists that have passed the required competency and certification exams.




By valariearthur

Metal Fabrication


With a high degree of proven excellence in delivering quality metal fabrication services, 4 Metal Fabricators will guarantee the best. This ranges from our specialty area of metal part manufacturing from your drawings with a fast turn around to the engineering designs and prototypes manufacturing at the most affordable and pocket friendly rates. We thereby offer you a wide array of high precision metal fabrication services and products at our shops. To us, creating the most versatile metal fabrication solutions to you is our concern!


Our metal fabrication processes are computerized making our designs the most competitive in the market. In addition to this, we have adequate staff to undertake the most complex assignments to fine detail with no lee way for industrial manufacturer’s faults. This is often done trough thorough testing of the equality of our product before their dispatch to the clients for use. As a result, we offer what we can attest to as in perfect working condition. More to this, you have a wide array of metals from which your precision fabrication can be done on. These include aluminum, titanium, steel and stainless steel among others.


In our quest for the most competitive metal fabrication solutions, we deploy heavy mechanization and we are thus able to offer you industry lead products at the most affordable rates. We also deploy and use high quality materials. Consequently, our products are incomparable; with our quality and services being excellent.  With our in depth knowledge of the industry needs, we are able to craft formidable metal fabrication solutions that will stand the test of time.


Lastly, we also employ highly qualified staff; from our engineers to the crafts men who undertake our assignments. This gives us a competitive edge as we are able to deliver the much coveted industry lead designs and models. The team of experts has also undergone strict internal evaluation and vetting with the most qualified staff in a particular field being allocated to undertake the most challenging projects such as yours. However, this means nothing but our quest for the best! With the vast experience in various projects undertaken since inception, the staffs are sure of being able to deliver the best quality. In addition to this, the staffs are well merged with the excellent customer service team whose unfailing role has led us see the company scales to higher heights. Consequently, your choice to work with 4 metal fabricators is working with the industry best brains for the best fabrication solutions!




By valariearthur

Dining furniture Mississauga- Why Dining Furniture is Important

Looking for high quality dining furniture Mississauga? It is possible to find the best quality furniture here. Before you even plunge into buying this furniture, you may need to know why you should have it in the first place. Although you can choose to have your meals from anywhere, it makes great sense to use the dining room or dining space. Here, you have the opportunity of meeting and interacting with your family every day, probably at 6 pm. As you dine together, you get to connect even more and to understand the needs of each and every member.

Bear in mind also that dining furniture allows you, and your family, to practice one of the most exciting pleasures of life, eating. Besides being a great pleasure of life, we also know the role that food plays in determining your health.

Daily family reunions, and accomplishment of the greatest desires of life, eating, are accomplished in the dining room. Because this room or space is that important, its furniture should also be great. It should comfortable to facilitate the purpose that the room is supposed to fulfill. As you plan your plan to buy dining furniture Mississauga, ensure that the furniture is worth of being used in a room that is one of the most important in your house.
Besides making dining experience exceptional, dining furniture also completes your house. Without it, your house would look awkward. This furniture raises the aesthetic value of your dining room and that of the entire house.

Before purchasing exceptionally high quality dining furniture Mississauga, remember the purpose that it will be put into. This furniture facilitates daily family reunions. Nothing is more important than this. In that case, strive to choose furniture that will always make these reunions enjoyable. Also bear in mind that the furniture helps you, and your family, accomplish a great assignment of nature, and that is eating. Equally important, dining furniture enhances the aesthetic value of the dining room and the entire house.

By valariearthur