Paper is a thin material produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets. It is a versatile material with many uses including for writing, packaging, cleaning, and more. Sheets of paper can be cut and folded into shapes and forms, with common paper sizes including letter and A4.
This document discusses corrosion under insulation (CUI), which occurs in the space between insulating material and metal surfaces in various industries like oil & gas, chemicals, and food processing. CUI is caused by water collecting in this space from sources like rain, leaks, or condensation. It can lead to localized corrosion and wall loss. The document examines major factors that influence CUI like temperature, insulation design, and environmental conditions. It also identifies specific units and areas that are susceptible to CUI, such as pipes near cooling towers or steam vents. The appearance of CUI and methods to prevent it through coatings and insulation practices are described. Inspection and monitoring techniques for CUI are also discussed, including a probe array sensor
Corrosion Under Insulation Inspection In Ammonia Urea PlantAsirul Hoq
This document discusses corrosion under insulation (CUI) inspection planning for an ammonia and urea plant. It defines CUI and outlines the susceptible materials, temperature ranges, mechanisms, and locations. It provides details on organizing the inspection work, developing a schedule, selecting inspection types, and identifying at-risk equipment. Pipeline CUI is also addressed, highlighting common locations and examples found. The conclusion emphasizes the challenges of CUI detection and recommends design improvements and coatings to reduce corrosion risks over the long-term.
This document discusses corrosion under insulation (CUI). It occurs when moisture accumulates between insulation and equipment, trapping corrosive components. Factors like moisture, corrosive fluids, and elevated temperatures from insulation can cause corrosion rates of around 4 mm per year in carbon steel. Visual inspection is commonly used to detect CUI but has limitations. Preventing CUI involves stopping water penetration into insulation and using protective barriers to isolate the metal surface from corrosives. Improving insulation system designs and maintaining seals are recommended prevention methods.
Concrete is today’s main building material. Modern infrastructure, road and bridge construction would be inconceivable without concrete as would skyscrapers and industrial buildings. Concrete is a versatile building material used especially in civil engineering in combination with steel. Concrete and reinforced concrete are building materials that have significantly changed construction. Despite concrete’s durability, serious concrete damage that endangers a building’s existence frequently occurs. The main cause of concrete damage is reinforcement steel corrosion due to environmental influences.
Quench cracks occur due to stresses that develop during the martensitic transformation when quenching steel. As the softer austenite in the core of the part transforms to harder martensite, it takes up less volume than the martensite that has already formed at the surface. This restricts the volume change and puts the surface martensite into tension. If the stress exceeds the strength of the martensite, cracks will form at the surface and propagate inward. Common causes of quench cracking include overheating the steel, using an improper quenchant, inadequate tempering after quenching, and stress concentrators in the part geometry. Proper heat treatment procedures and part design are needed
Weld Purging ~ Corrosion Problems in Stainless Steel by WeldingRon Sewell
Abstract
Corrosion is not uncommon in stainless steels, despite their name. Salt water environments in particular can give rise to corrosion and this is even noticeable at domestic level where cutlery discolours in mild salt solutions during dishwashing cycles. Loss of corrosion resistance during welding takes place when oxygen levels in shield and purge gases are high enough to deplete the chromium content.
This document provides a review of corrosion under insulation (CUI), discussing key factors and mechanisms. It summarizes that CUI occurs via a three step process: 1) water ingress, 2) water accumulation under insulation, and 3) dissolution of corrosive species. Five important factors for CUI are discussed: insulation material, coating material, substrate material, atmosphere, and design. Carbon steel is susceptible to general and localized corrosion from CUI, while stainless steel risks pitting and stress corrosion cracking. Proper coating and design can prevent the water accumulation and corrosion processes that cause CUI.
Customer Bulletin 0610 Polyisocyanurate vs. Cellular Glass InsulationJoe Hughes
This Customer Bulletin is another in our series of white papers aimed at providing our clients, engineers, contractors, fabricators, and friends with objective information on our products and those of our competitors. This Bulletin focuses on a comparison of the physical properties of closed cell polyisocyanurate (PIR or polyiso) rigid foam insulation with those of cellular glass insulation for below ambient applications such as chilled water through cryogenic application where moisture intrusion or condensation can be an issue.
This document discusses corrosion under insulation (CUI), which occurs in the space between insulating material and metal surfaces in various industries like oil & gas, chemicals, and food processing. CUI is caused by water collecting in this space from sources like rain, leaks, or condensation. It can lead to localized corrosion and wall loss. The document examines major factors that influence CUI like temperature, insulation design, and environmental conditions. It also identifies specific units and areas that are susceptible to CUI, such as pipes near cooling towers or steam vents. The appearance of CUI and methods to prevent it through coatings and insulation practices are described. Inspection and monitoring techniques for CUI are also discussed, including a probe array sensor
Corrosion Under Insulation Inspection In Ammonia Urea PlantAsirul Hoq
This document discusses corrosion under insulation (CUI) inspection planning for an ammonia and urea plant. It defines CUI and outlines the susceptible materials, temperature ranges, mechanisms, and locations. It provides details on organizing the inspection work, developing a schedule, selecting inspection types, and identifying at-risk equipment. Pipeline CUI is also addressed, highlighting common locations and examples found. The conclusion emphasizes the challenges of CUI detection and recommends design improvements and coatings to reduce corrosion risks over the long-term.
This document discusses corrosion under insulation (CUI). It occurs when moisture accumulates between insulation and equipment, trapping corrosive components. Factors like moisture, corrosive fluids, and elevated temperatures from insulation can cause corrosion rates of around 4 mm per year in carbon steel. Visual inspection is commonly used to detect CUI but has limitations. Preventing CUI involves stopping water penetration into insulation and using protective barriers to isolate the metal surface from corrosives. Improving insulation system designs and maintaining seals are recommended prevention methods.
Concrete is today’s main building material. Modern infrastructure, road and bridge construction would be inconceivable without concrete as would skyscrapers and industrial buildings. Concrete is a versatile building material used especially in civil engineering in combination with steel. Concrete and reinforced concrete are building materials that have significantly changed construction. Despite concrete’s durability, serious concrete damage that endangers a building’s existence frequently occurs. The main cause of concrete damage is reinforcement steel corrosion due to environmental influences.
Quench cracks occur due to stresses that develop during the martensitic transformation when quenching steel. As the softer austenite in the core of the part transforms to harder martensite, it takes up less volume than the martensite that has already formed at the surface. This restricts the volume change and puts the surface martensite into tension. If the stress exceeds the strength of the martensite, cracks will form at the surface and propagate inward. Common causes of quench cracking include overheating the steel, using an improper quenchant, inadequate tempering after quenching, and stress concentrators in the part geometry. Proper heat treatment procedures and part design are needed
Weld Purging ~ Corrosion Problems in Stainless Steel by WeldingRon Sewell
Abstract
Corrosion is not uncommon in stainless steels, despite their name. Salt water environments in particular can give rise to corrosion and this is even noticeable at domestic level where cutlery discolours in mild salt solutions during dishwashing cycles. Loss of corrosion resistance during welding takes place when oxygen levels in shield and purge gases are high enough to deplete the chromium content.
This document provides a review of corrosion under insulation (CUI), discussing key factors and mechanisms. It summarizes that CUI occurs via a three step process: 1) water ingress, 2) water accumulation under insulation, and 3) dissolution of corrosive species. Five important factors for CUI are discussed: insulation material, coating material, substrate material, atmosphere, and design. Carbon steel is susceptible to general and localized corrosion from CUI, while stainless steel risks pitting and stress corrosion cracking. Proper coating and design can prevent the water accumulation and corrosion processes that cause CUI.
Customer Bulletin 0610 Polyisocyanurate vs. Cellular Glass InsulationJoe Hughes
This Customer Bulletin is another in our series of white papers aimed at providing our clients, engineers, contractors, fabricators, and friends with objective information on our products and those of our competitors. This Bulletin focuses on a comparison of the physical properties of closed cell polyisocyanurate (PIR or polyiso) rigid foam insulation with those of cellular glass insulation for below ambient applications such as chilled water through cryogenic application where moisture intrusion or condensation can be an issue.
Program for Prevention of CUI at a RefinerySharon Hart
The document outlines a program to minimize occurrences and severity of corrosion under insulation (CUI) at an oil refinery. It identifies 12 common problems that can lead to CUI and recommends solutions. General recommendations include using calcium silicate insulation for temperatures over 350°F, cellular glass below 350°F, and continuing use of aluminum jacketing with a moisture barrier and removable/reusable blankets where needed. Implementing the solutions and recommendations would enhance safety by reducing CUI and extending the life of insulated pipes and equipment at the refinery.
Corrosion is a major concern for metallic implants placed in the human body. The various types of corrosion that can occur include uniform corrosion, pitting corrosion, intergranular corrosion, stress corrosion cracking, and galvanic corrosion. Pitting corrosion and stress corrosion cracking are particularly dangerous as they can cause unexpected catastrophic failure. Passive films and coatings like hydroxyapatite can provide corrosion resistance and improve biocompatibility of implants. The deposition technique used depends on the material and desired film properties. Corrosion of implants can release toxic ions and lead to inflammation or tumor growth if fragments remain in the body.
This document discusses different types of coatings used to prevent corrosion of metals and evaluates their effectiveness. It focuses on introducing a new coating called Rust Bullet. Rust Bullet uses a moisture-cured urethane that penetrates rust and forms a protective layer of metallic flakes within the resin. This creates an armor that shields the underlying metal while also dehydrating rust. The coating has advantages over traditional zinc-rich coatings and epoxy alternatives in terms of durability, environmental friendliness, ease of application, and ability to permanently stop corrosion. Testing shows Rust Bullet provides stronger protection than competitors and can withstand demanding conditions.
As the oil and gas market moves towards new corrosion-resistant materials and alloys, specifying products has become increasingly complex.
When no single material performs well in every application, how can specifiers determine the best fit for a project? And what can be done to predict the expected service life of a component?
This technical seminar, run by Parker on its stand at the major oil and gas event Offshore Europe 2017, looks at:
• Common types of corrosion and their triggers
• Key factors to consider when selecting materials for a project
• Different manufacturer perspectives and the science behind their arguments
• Risks associated with mixing dissimilar materials.
About Clara Moyanno: As an innovation engineer and expert metallurgist working across the globe, Ms. Moyanno, innovation engineer with Parker Hannifin, deals with all sorts of challenges. She is often involved in discussions on materials selection, including advice to oil and gas producers working on new platforms around the world.
Clara specializes in areas such as tackling corrosion, and materials selection for design specifications. She also advises on quality certifications and regulations around the manufacturing of metals.
Learn more http://parker.com/ipd
Stress corrosion cracking is the failure of a normally ductile metal caused by the combined effect of tensile stress and a corrosive environment. Three factors are required for stress corrosion cracking to occur: a susceptible material, a tensile stress (either applied or residual), and a corrosive environment. Stress corrosion cracking leads to the formation of cracks that propagate in the material over time and eventually result in sudden brittle fracture.
Corrosion is the deterioration of materials through chemical reactions with the environment. It refers mainly to metals but can also affect other materials like plastics and concrete. Corrosion can have serious economic and safety consequences by reducing strength, causing equipment downtime, and loss of surface properties. It can lead to failures and expensive replacements even when only a small amount of metal is destroyed. Underground pipes and electronic components are especially vulnerable. The effects of corrosion are influenced by factors like water flow, exposure to sea water, contact between dissimilar metals, and lack of protective coatings.
Corrosion is the deterioration of metals due to chemical or electrochemical reactions with their environment. There are several types of corrosion including general corrosion, pitting corrosion, intergranular corrosion, stress corrosion, crevice corrosion, galvanic corrosion, erosion corrosion, cavitation corrosion, and fretting corrosion. The document discusses the causes and characteristics of each type. Corrosion can be prevented by selecting the proper metal type, protective coatings, environmental controls, sacrificial anodes, corrosion inhibitors, and design modifications. Surface pretreatments and coatings are important for inhibiting corrosion.
This document discusses surface treatment technologies for stainless steel parts used in high-tech industries. It focuses on electrolytic polishing, which improves surface cleanliness and reduces outgassing in vacuum applications. Electrolytic polishing reduces surface roughness, suppresses hydrogen absorption, and enriches the surface with elements like chromium and nickel. It can lower the outgassing rate by a factor of 600 compared to chemical cleaning alone. The document also outlines other surface treatments like grinding, pickling, and passivating used to clean stainless steel and restore corrosion resistance. It emphasizes that contamination-free fluids and facilities are essential for high-purity surfaces in high-tech applications.
Stainless steels contain 10.5-30% chromium which forms a passive oxide layer protecting the steel from corrosion. Common types include martensitic, ferritic, austenitic, and duplex stainless steels. Martensitic stainless steels can be hardened through heat treatment while ferritic stainless steels have higher ductility and corrosion resistance. Duplex stainless steels have a mixed austenite and ferrite structure providing high strength and pitting/stress corrosion resistance. Austenitic stainless steels have excellent ductility and toughness down to cryogenic temperatures and are widely used in chemical plants and food processing. Proper welding techniques are required to prevent issues like sensitization, hot cracking, and sigma
This document discusses engineering considerations for corrosion including materials selection, testing, equipment design, and inspection. Key points covered include:
- Evaluating operating conditions and process components to select appropriate construction materials.
- Testing materials to understand corrosion behavior and ensure suitability for the application.
- Designing equipment to minimize corrosion, such as avoiding crevices, using proper welding techniques, and including corrosion allowances.
- Inspecting plants regularly to identify corrosion issues, using visual checks, ultrasonics, and boroscopes depending on the area inspected.
Borosilicate glass has unique chemical and physical properties that make it well-suited for use in the chemical, food, pharmaceutical, and other industries. It has outstanding corrosion resistance, is transparent and inert. Borosilicate glass can withstand high temperatures up to 250°C and pressures depending on the component size. It also has low thermal expansion, is electrically insulating, and can be combined with other materials like PTFE. Borosilicate glass 3.3 is commonly used for its balance of properties.
Crevice corrosion is a localized form of corrosion that occurs in confined, shielded areas where solutions can stagnate, such as under gaskets, fasteners, or deposits. It results from differences in concentration of oxygen and chlorides between the crevice (anode) and outside of it (cathode), which sets up an electrochemical cell. Factors like crevice geometry and chemistry, material composition, and environmental conditions affect its occurrence. It is a significant issue for corrosion-resistant alloys in systems with pure water chemistry and can cause component failure while appearing as minimal overall material loss, making it difficult to detect. Methods to prevent it include eliminating crevices, using solid gaskets, employing higher-alloy materials,
rust free india and rest of world civil structures like dam roads bridges life increased to decades and many more decades
railway coaches ships aeroplanes....................life increased to decades and decades
regards
harish (harry)shrma+919812008556
laserrobo@gmail.com
Corrosion Barriers or Mitigation presentationEmeka Nwafor
This document discusses corrosion barriers and assurance for a seawater injection system. It lists various types of corrosion threats and prevention methods. Corrosion barriers include material selection, application of chemicals like inhibitors and oxygen scavengers, pipeline design considerations, and coatings. Assurance methods involve monitoring corrosion rates, oxygen, bacteria, bisulfite and chlorine levels, and total suspended solids to ensure corrosion barriers remain effective.
This document discusses various methods for protecting metals from corrosion. It first defines corrosion as the deterioration of materials through chemical interaction with the environment. It then explains that oxygen, humidity, and chemical salts are common causes of corrosion. The document goes on to describe several protection methods, including barrier protection using paints, oils, or electroplating; sacrificial protection using more reactive metals; and cathodic protection of underground pipes using more electropositive anodes.
Acid Corrosion Inhibitor is designed specifically to inhibit the acidic attack on various metals such as Brass, Copper, Tin, Nickel, Zinc, Lead, Galvanized surface and all other type of steel.
The document discusses various types of corrosion including uniform corrosion, pitting corrosion, crevice corrosion, galvanic corrosion, stress corrosion cracking, intergranular corrosion, dealloying, and erosion corrosion. It also examines factors that influence corrosion such as the nature of the metal, temperature, moisture, pH, and impurities in the environment. Finally, it reviews methods to control corrosion including material selection, coatings, cathodic protection, and design considerations.
Customer Bulletin 0611 Insulant Impact on Corrosion in Steel Piping Applicati...Dyplast Products
Corrosion is defined by the National Association of Corrosion Engineers as “the deterioration of a material, usually a metal, by reaction with its environment.” Corrosion under insulation (CUI) is not a distinct form of corrosion; rather it refers to the location where pipe wall material deterioration is occurring—underneath the insulation material and on the external surfaces of piping. CUI (and the corrosion of metal jackets and banding which is not addressed herein) is a recognized problem that must be addressed by designers, specifiers, and end-users. CUI can occur under any type of thermal insulation. The type of corrosion will depend on the metallurgy of the pipe as well as the mix of corrosive elements - - understanding that corrosive elements can be introduced during pipe production, pipe shipping/storage, installation, insulation contact, process liquid contact, weather, or other environmental influences.
The document discusses corrosion under insulation (CUI) and provides information on why it occurs, how to detect it, and how to prevent it. CUI is corrosion that occurs underneath insulation on pipes and equipment and can lead to leaks and safety incidents if undetected. It occurs when water or moisture penetrates the insulation system, often through breaks in protective coverings. Various techniques are used to detect CUI, including visual inspection after removing some or all of the insulation, as well as nondestructive methods like moisture meters and infrared thermography. Targeted inspection of areas susceptible to water penetration and insulation damage is recommended.
Program for Prevention of CUI at a RefinerySharon Hart
The document outlines a program to minimize occurrences and severity of corrosion under insulation (CUI) at an oil refinery. It identifies 12 common problems that can lead to CUI and recommends solutions. General recommendations include using calcium silicate insulation for temperatures over 350°F, cellular glass below 350°F, and continuing use of aluminum jacketing with a moisture barrier and removable/reusable blankets where needed. Implementing the solutions and recommendations would enhance safety by reducing CUI and extending the life of insulated pipes and equipment at the refinery.
Corrosion is a major concern for metallic implants placed in the human body. The various types of corrosion that can occur include uniform corrosion, pitting corrosion, intergranular corrosion, stress corrosion cracking, and galvanic corrosion. Pitting corrosion and stress corrosion cracking are particularly dangerous as they can cause unexpected catastrophic failure. Passive films and coatings like hydroxyapatite can provide corrosion resistance and improve biocompatibility of implants. The deposition technique used depends on the material and desired film properties. Corrosion of implants can release toxic ions and lead to inflammation or tumor growth if fragments remain in the body.
This document discusses different types of coatings used to prevent corrosion of metals and evaluates their effectiveness. It focuses on introducing a new coating called Rust Bullet. Rust Bullet uses a moisture-cured urethane that penetrates rust and forms a protective layer of metallic flakes within the resin. This creates an armor that shields the underlying metal while also dehydrating rust. The coating has advantages over traditional zinc-rich coatings and epoxy alternatives in terms of durability, environmental friendliness, ease of application, and ability to permanently stop corrosion. Testing shows Rust Bullet provides stronger protection than competitors and can withstand demanding conditions.
As the oil and gas market moves towards new corrosion-resistant materials and alloys, specifying products has become increasingly complex.
When no single material performs well in every application, how can specifiers determine the best fit for a project? And what can be done to predict the expected service life of a component?
This technical seminar, run by Parker on its stand at the major oil and gas event Offshore Europe 2017, looks at:
• Common types of corrosion and their triggers
• Key factors to consider when selecting materials for a project
• Different manufacturer perspectives and the science behind their arguments
• Risks associated with mixing dissimilar materials.
About Clara Moyanno: As an innovation engineer and expert metallurgist working across the globe, Ms. Moyanno, innovation engineer with Parker Hannifin, deals with all sorts of challenges. She is often involved in discussions on materials selection, including advice to oil and gas producers working on new platforms around the world.
Clara specializes in areas such as tackling corrosion, and materials selection for design specifications. She also advises on quality certifications and regulations around the manufacturing of metals.
Learn more http://parker.com/ipd
Stress corrosion cracking is the failure of a normally ductile metal caused by the combined effect of tensile stress and a corrosive environment. Three factors are required for stress corrosion cracking to occur: a susceptible material, a tensile stress (either applied or residual), and a corrosive environment. Stress corrosion cracking leads to the formation of cracks that propagate in the material over time and eventually result in sudden brittle fracture.
Corrosion is the deterioration of materials through chemical reactions with the environment. It refers mainly to metals but can also affect other materials like plastics and concrete. Corrosion can have serious economic and safety consequences by reducing strength, causing equipment downtime, and loss of surface properties. It can lead to failures and expensive replacements even when only a small amount of metal is destroyed. Underground pipes and electronic components are especially vulnerable. The effects of corrosion are influenced by factors like water flow, exposure to sea water, contact between dissimilar metals, and lack of protective coatings.
Corrosion is the deterioration of metals due to chemical or electrochemical reactions with their environment. There are several types of corrosion including general corrosion, pitting corrosion, intergranular corrosion, stress corrosion, crevice corrosion, galvanic corrosion, erosion corrosion, cavitation corrosion, and fretting corrosion. The document discusses the causes and characteristics of each type. Corrosion can be prevented by selecting the proper metal type, protective coatings, environmental controls, sacrificial anodes, corrosion inhibitors, and design modifications. Surface pretreatments and coatings are important for inhibiting corrosion.
This document discusses surface treatment technologies for stainless steel parts used in high-tech industries. It focuses on electrolytic polishing, which improves surface cleanliness and reduces outgassing in vacuum applications. Electrolytic polishing reduces surface roughness, suppresses hydrogen absorption, and enriches the surface with elements like chromium and nickel. It can lower the outgassing rate by a factor of 600 compared to chemical cleaning alone. The document also outlines other surface treatments like grinding, pickling, and passivating used to clean stainless steel and restore corrosion resistance. It emphasizes that contamination-free fluids and facilities are essential for high-purity surfaces in high-tech applications.
Stainless steels contain 10.5-30% chromium which forms a passive oxide layer protecting the steel from corrosion. Common types include martensitic, ferritic, austenitic, and duplex stainless steels. Martensitic stainless steels can be hardened through heat treatment while ferritic stainless steels have higher ductility and corrosion resistance. Duplex stainless steels have a mixed austenite and ferrite structure providing high strength and pitting/stress corrosion resistance. Austenitic stainless steels have excellent ductility and toughness down to cryogenic temperatures and are widely used in chemical plants and food processing. Proper welding techniques are required to prevent issues like sensitization, hot cracking, and sigma
This document discusses engineering considerations for corrosion including materials selection, testing, equipment design, and inspection. Key points covered include:
- Evaluating operating conditions and process components to select appropriate construction materials.
- Testing materials to understand corrosion behavior and ensure suitability for the application.
- Designing equipment to minimize corrosion, such as avoiding crevices, using proper welding techniques, and including corrosion allowances.
- Inspecting plants regularly to identify corrosion issues, using visual checks, ultrasonics, and boroscopes depending on the area inspected.
Borosilicate glass has unique chemical and physical properties that make it well-suited for use in the chemical, food, pharmaceutical, and other industries. It has outstanding corrosion resistance, is transparent and inert. Borosilicate glass can withstand high temperatures up to 250°C and pressures depending on the component size. It also has low thermal expansion, is electrically insulating, and can be combined with other materials like PTFE. Borosilicate glass 3.3 is commonly used for its balance of properties.
Crevice corrosion is a localized form of corrosion that occurs in confined, shielded areas where solutions can stagnate, such as under gaskets, fasteners, or deposits. It results from differences in concentration of oxygen and chlorides between the crevice (anode) and outside of it (cathode), which sets up an electrochemical cell. Factors like crevice geometry and chemistry, material composition, and environmental conditions affect its occurrence. It is a significant issue for corrosion-resistant alloys in systems with pure water chemistry and can cause component failure while appearing as minimal overall material loss, making it difficult to detect. Methods to prevent it include eliminating crevices, using solid gaskets, employing higher-alloy materials,
rust free india and rest of world civil structures like dam roads bridges life increased to decades and many more decades
railway coaches ships aeroplanes....................life increased to decades and decades
regards
harish (harry)shrma+919812008556
laserrobo@gmail.com
Corrosion Barriers or Mitigation presentationEmeka Nwafor
This document discusses corrosion barriers and assurance for a seawater injection system. It lists various types of corrosion threats and prevention methods. Corrosion barriers include material selection, application of chemicals like inhibitors and oxygen scavengers, pipeline design considerations, and coatings. Assurance methods involve monitoring corrosion rates, oxygen, bacteria, bisulfite and chlorine levels, and total suspended solids to ensure corrosion barriers remain effective.
This document discusses various methods for protecting metals from corrosion. It first defines corrosion as the deterioration of materials through chemical interaction with the environment. It then explains that oxygen, humidity, and chemical salts are common causes of corrosion. The document goes on to describe several protection methods, including barrier protection using paints, oils, or electroplating; sacrificial protection using more reactive metals; and cathodic protection of underground pipes using more electropositive anodes.
Acid Corrosion Inhibitor is designed specifically to inhibit the acidic attack on various metals such as Brass, Copper, Tin, Nickel, Zinc, Lead, Galvanized surface and all other type of steel.
The document discusses various types of corrosion including uniform corrosion, pitting corrosion, crevice corrosion, galvanic corrosion, stress corrosion cracking, intergranular corrosion, dealloying, and erosion corrosion. It also examines factors that influence corrosion such as the nature of the metal, temperature, moisture, pH, and impurities in the environment. Finally, it reviews methods to control corrosion including material selection, coatings, cathodic protection, and design considerations.
Customer Bulletin 0611 Insulant Impact on Corrosion in Steel Piping Applicati...Dyplast Products
Corrosion is defined by the National Association of Corrosion Engineers as “the deterioration of a material, usually a metal, by reaction with its environment.” Corrosion under insulation (CUI) is not a distinct form of corrosion; rather it refers to the location where pipe wall material deterioration is occurring—underneath the insulation material and on the external surfaces of piping. CUI (and the corrosion of metal jackets and banding which is not addressed herein) is a recognized problem that must be addressed by designers, specifiers, and end-users. CUI can occur under any type of thermal insulation. The type of corrosion will depend on the metallurgy of the pipe as well as the mix of corrosive elements - - understanding that corrosive elements can be introduced during pipe production, pipe shipping/storage, installation, insulation contact, process liquid contact, weather, or other environmental influences.
The document discusses corrosion under insulation (CUI) and provides information on why it occurs, how to detect it, and how to prevent it. CUI is corrosion that occurs underneath insulation on pipes and equipment and can lead to leaks and safety incidents if undetected. It occurs when water or moisture penetrates the insulation system, often through breaks in protective coverings. Various techniques are used to detect CUI, including visual inspection after removing some or all of the insulation, as well as nondestructive methods like moisture meters and infrared thermography. Targeted inspection of areas susceptible to water penetration and insulation damage is recommended.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
357 - 360, Badiu 2 RESEARCH ON DEGRADATION BY CORROSION OF SOME COMPONENTS OF...EDUARD C BADIU
This document discusses corrosion of components in building roofs. It summarizes that corrosion is caused by the interaction of materials with their environment in the presence of moisture, oxygen, and heat. Galvanic corrosion can occur when dissimilar metals are in contact in this environment. The document recommends selecting compatible materials or using protective coatings and insulators to prevent galvanic corrosion. It also discusses specific corrosion issues for steel roof decks, fasteners, and fasteners in contact with preservative-treated wood.
This document discusses factors that influence the serviceability and durability of concrete, including climate, temperature, chemicals, wear and erosion, design errors, and corrosion. It covers the effects of cover thickness and cracking, as well as methods of corrosion protection like corrosion inhibitors, corrosion resistant steels, coatings, and cathodic protection. The document also examines causes of corrosion like carbonation, chloride penetration, and sulfate attack, and methods to improve concrete durability.
Canada Metal: Lead sheet metal for nuclear shielding, Constructioncanadametal
This document discusses sheet lead and its various applications. It begins by providing an overview of sheet lead's properties such as its high density, malleability, corrosion resistance, and thermal conductivity. It then discusses sheet lead's common uses in roofing, flashing, waterproofing, and soundproofing based on these properties. The document provides details on sheet lead specifications and thickness classes. It also summarizes the major architectural and construction applications of sheet lead and the advantages it provides for each one.
This is a ppt. on protection from corrosion of steel reinforcement in concrete structures. I had prepared this as a part of my class seminar. I made this by referring to the books on Concrete Technology by M.S.Shetty and M.L.Gambhir
The document discusses various repair, rehabilitation, and retrofitting techniques for structures. It covers common types of repairs for concrete structures, such as epoxy injection for cracks. It also discusses strengthening methods like jacketing and underpinning. Underpinning techniques include mass concrete underpinning, beam and base underpinning, and mini-piled underpinning. The document also addresses fire damage to structures and the effects of fire on concrete properties at different temperatures. Finally, it covers corrosion prevention methods for reinforcement like coatings, fly ash, and electrochemical treatments.
This document discusses repair, rehabilitation, and retrofitting techniques for structures. It covers common types of repairs for concrete structures, such as epoxy injection grouting to repair cracks. It also discusses how fire can damage structures and how concrete properties are affected at different temperatures during a fire. Finally, it outlines various corrosion prevention and crack repair methods that can be used to strengthen and extend the life of structures.
ProCoat Specialities provides corrosion protection services including surface preparation, coating application, and inspections. They believe thorough examination and analysis is needed to select the appropriate protection mechanism for different substrates and environments. ProCoat focuses on high quality surface preparation and coating application according to international standards. Their services also include educating clients, inspection reports, and turn-key corrosion protection solutions.
Use of Sheet Lead as the Protective Shieldingcanadametal
Sheet lead can be used for the different purposes in the applications like roofing & flashing, waterproofing, noise control, and protective radiation shielding. The typical uses of radiation shielding includes space shielding, mobile lead screen, lead shielded containers, and nuclear reactor shielding. For more information, contact to the Canada Metal North America.
Visit: http://www.canadametal.com/products/lead/sheet-lead/
Corrosion is the spontaneous reaction between a material like steel and its environment that degrades the material over time. For ships, corrosion poses a major problem as it can compromise the structural integrity of the vessel. There are two main methods to prevent corrosion - cathodic protection, which makes the structure negative to corrosion, and coatings, which act as a barrier between the steel and environment. Effective coatings must adhere well to the steel, be impermeable to water and oxygen, and have a thickness and pigmentation that limits penetration over the life of the coating.
Corrosion of steel reinforcement in concrete is an electrochemical process that occurs when water and oxygen reach the steel. It results in rust formation that expands and cracks the concrete. Chlorides are a major cause as they penetrate the protective oxide layer on the steel. Methods to prevent corrosion include coating the rebars, using fly ash or silica fume in concrete to reduce permeability, cathodic protection through sacrificial or impressed current anodes, and barrier coatings on structures. Thermally sprayed zinc and aluminum coatings provide both barrier and sacrificial protection of steel.
This document discusses cathodic protection as a technique to prevent corrosion of reinforced concrete structures. It involves introducing a more negatively charged anode material into the concrete to divert electrons away from the reinforcing steel and prevent corrosion. This provides permanent protection for the 100+ year design life of structures. Case studies show it has been successfully applied to new cooling water structures in the Middle East using Elgard mixed metal oxide ribbon anodes secured to the reinforcement before pouring concrete.
Corrosion causes tens of billions of dollars in damage annually in the US. It deteriorates materials through chemical, electro-chemical, or mechanical-chemical attack. Common types of corrosion for centrifugal pumps include general corrosion, crevice corrosion, pitting corrosion, galvanic corrosion, and erosion corrosion. Proper material selection is important to resist corrosion and extend pump life. Tests should be conducted to evaluate materials under similar operating conditions before finalizing the selection.
This document describes experiments conducted to develop an improved technique for removing glob top encapsulant from integrated circuit packages during failure analysis. The current method using fuming nitric acid is unable to remove glob top without damaging the package. Experiments using concentrated sulfuric acid at high temperatures were performed on dummy samples. Key findings include: 1) Boiling concentrated sulfuric acid was able to successfully remove glob top and expose the silicon die and bond wires without inducing damage to the package. 2) Fuming nitric acid can over-etch the substrate and cause issues like misplaced die before fully removing the glob top. 3) Proper safety precautions must be followed when using concentrated sulfuric acid due to its corrosive and oxidizing properties.
Elysator Professional Summary VDI 2035, Part 2Roger Conarroe
This document summarizes guidelines from VDI 2035 Part 2 on preventing corrosion in hydronic heating systems. Key factors that influence corrosion are dissolved oxygen content, electrical conductivity, and pH of the water. To minimize corrosion, oxygen content should be less than 0.1 mg/L for low-salinity systems and less than 0.02 mg/L for saline systems, while maintaining pH between 8.2-10. Proper sealing and limiting oxygen entry into the system through components like expansion vessels and tubing is important to control these factors and prevent corrosion damage to system materials like steel, copper, aluminum, and others.
Structural health monitoring and concrete protection methods are needed to protect structures from environmental damage and corrosion. Concrete protection includes hydrophobic impregnation, painting, oils and sealers to prevent water and chemical ingress. Reinforcement can be protected through galvanization, corrosion-inhibiting admixtures, and cathodic protection. Self-regulating anodes provide galvanic protection to reinforced concrete through sacrificial corrosion of the anode material. Structural health monitoring assesses structural condition over time using automated methods to predict remaining lifespan.
This document summarizes a presentation on corrosion under insulation (CUI) and coatings for mitigating CUI. It discusses how CUI occurs due to moisture ingress under insulation and temperature cycling. Several coating types are described that can provide barrier protection for steel under insulation, including epoxy phenolic, silicone acrylic, thermal spray aluminum, titanium modified inorganic copolymers, and inert multipolymeric matrix paints. Test methods for evaluating CUI coatings like cyclic pipe tests and CUI chambers are also summarized. Real-world case studies show how some coatings have performed well under long-term cyclic service conditions.
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1. Paper No.
00000 (Official use)
NIGIS * CORCON 2016 * Sept. 18 – 21, 2016 * New Delhi
Copyright 2016 by NIGIS. The material presented and the views expressed in this paper are solely those of the author(s) and do not necessarily by NIGIS.
Corrosion under Insulation – Facts and Prevent
KUMAR KOLUR VADIVELU
ABSTRACT
Corrosion under insulation (CUI) has become one of the utmost important mechanical integrity
issues with the following sectors chemical plants, petroleum refineries, power generating
facilities and other plants in all over the world.
Corrosion under insulation is very difficult to detect and find-out because of the insulation
material hide the beneath problem.
Old-style methods of addressing this issue include removal of insulation for visual inspection
operating temperatures ranges from -3°C (25 ºF) to 150 °C (300 ºF.) This method will not
address about cold service and cyclic service operation.
Oxygen with moisture is the largest promoting factor for corrosion. Under the insulation the
evaporated media transferred from one place to another place and not allowing the evaporated
media in to the environment so this is leads to the corrosion under insulation.
Carbon and Stainless Steel with 300 Series are more susceptible for Corrosion under insulation
there are various reason to cause corrosion. But the process upsets or cyclic process conditions
will be the primary factor.
This paper focus about the different type of corrosion under insulation it is include the substrate
being protected and cladding . material. The primary reasons to promote the corrosion under
insulation. Discussion about the selection of insulation material, impact on coating material, CUI
detection logics and modern industry practice to detect the CUI.
This paper discuss about the possibility of CUI. The best way to minimize or detect if any failure
occur always refer to relevant standards.
Key words:
Corrosion under Insulation (CUI), Galvanic corrosion, Acid, alkaline corrosion, weather barriers. Insulation
material, Coating
2. NIGIS * CORCON 2016 * Sept. 18 – 21, 2016 * New Delhi
Copyright 2016 by NIGIS. The material presented and the views expressed in this paper are solely those of the author(s) and do not necessarily by NIGIS.
Corrosion under Insulation
Is a severe form of localized external corrosion that occurs in carbon and low alloy steel
equipment that has been insulated. This form of corrosion occurs when water is absorbed by or
collected in the insulation. The equipment begins to corrode as it is exposed to water and
oxygen. CUI is common in refineries and process plants that typically operate equipment at high
temperatures (Source_ Wiki).
Type of Corrosion under Insulation
The following type of corrosion is mostly occurs under the Insulation
Galvanic Corrosion
Alkaline or Acidic Corrosion
Chlorine stress corrosion
Galvanic couple occurs when two dissimilar material contact together based on Potential
difference of both metals. The most active material corrode first compare to least active metal,
in this concept the insulation material when wet condition the contaminated (Salt) electrolyte
that allows a current between insulated material and outer jacket or its accessories, The degree
and rigorousness of the attack on the less noble metal depends not only on the difference in
potential of the two metals, but also on their comparative areas.
Alkaline or Acidic corrosion results when contaminants in the moisture or vapor are present in
certain type of insulation material. For hot service above 300o
F, (150°C) most of the water is
driven off and the contaminants with water vapor may condense at the edge of the insulation
jacket, based on the contaminate type whether acidic or alkali in the condensed moisture react
with the insulating jacket resulting the corrosion particularly aluminum jackets affects well.
Alkaline contaminants react with aluminum jackets produce sever etching and pitting effect.
When chlorine present in the contaminants the pitting corrosion in the aluminum jacket is more
severe.
Cement type insulating material has alkaline in condition or it has alkaline chemical and water if
the steel immersed in the cement and still drying off particularly below 150°C(300°F), the
alkaline water may cause corrosion in case the insulating material stainless steel , aluminum or
Brass. Potable water is recommended to mix the insulating cement.
Corrosion due to Chloride is the combination of insulation material contain leachable chlorides
and austenitic-stainless-steel surfaces (300 Series), Chloride corrosion is more prone when the
moisture is present with the temperatures are higher than 60°C (140o F). Chloride
concentration is normally results from the evaporation of rain water, or in the industry water
utilized for fight fire or water used for process. In general the insulation jackets corroded due to
airborne salts blown thru air in the coastal regions.
3. NIGIS * CORCON 2016 * Sept. 18 – 21, 2016 * New Delhi
Copyright 2016 by NIGIS. The material presented and the views expressed in this paper are solely those of the author(s) and do not necessarily by NIGIS.
The Temperature of the surface particularly stainless steel and the chloride ion concentration
will directly proportional to the failure and the speed of crack propagation. Based on several
study shows below 60°C (176 °F) the moisture containing less than 510pmm Chloride ion and
pH is less than 10 considered safe. But at higher the temperatures with the lower levels of
Chloride ion can result in failure. (Referred API 571 Table 13.3M)
In practice, it should be expected that vaporization of the solution will certainly occur. Because
local concentration of chlorides takes place at the metal surface, the bulk concentration may be
of little importance. Above 200°C (390° F) the external stress-corrosion cracking is normally not
evidenced, the stress required to cause cracking of stainless steel may result from either the
fabrication, operation or shutdown activity.
Carbon steel, LTCS and low allow steels are prone to affect CUI with the following normal
operating temperature between -12°C (10°F) to 176. If the Carbon steel equipment’s spends
more than 10% of the total time below 175°C (350°F) should be considered more susceptible to
CUI.
Insulation surface normally water entering and diffusing inward will ultimately reach a region of
dry out at the hot pipe or equipment wall. Next to this dry out area is a region in which the pores
of the insulation are filled with a soaked contaminated solution-this includes any chlorides or
other ions. When a shutdown or process upset occurs and the metal-wall temperature fluctuates
(particularly falls).The zone of soaked contaminated solution passages into the metal wall. Upon
resuming the normal process condition (by reheating) the wall will momentarily be in contact
with the saturated solution (e.g., chlorides), and stress-corrosion cracking may activate.
How to Prevent CUI – General Practice
Foremost factor to minimize or avoiding the Corrosion under insulation is to keep liquid from
engrossing in to the insulation. Engrossing the water will limit the insulation property and
promote the corrosion under the insulation of equipment, piping and other insulated items.
Various factors may contribute to invade the water in to the insulated items in general those are
poor weathering, vibration and or abuse from the people.
Good practice to preventing CUI are
Selection of Insulation Type
Design of item being insulated
Protective paints and coatings
Weather barriers being used
Good Maintenance practices.
If an area is subject to spills or high humidity, special attention must be given to selecting the
insulation. Some insulation leave the system less sensitive to defects in weatherproofing or
paint films because the insulations are nonabsorbent and chemically nonreactive.
4. NIGIS * CORCON 2016 * Sept. 18 – 21, 2016 * New Delhi
Copyright 2016 by NIGIS. The material presented and the views expressed in this paper are solely those of the author(s) and do not necessarily by NIGIS.
Unluckily, the insulation are normally picked based on installed costs versus energy saved, and
not considered maintenance or corrosion cost. The selecting the insulation type the following
should be considered:
The cost of revamping the insulation if corrosion is spotted. Insulation should
be removed in limited sectors for inspection. If insulation is subject to damage
by abuse, the cost of periodic removal and replacement must be considered.
Insulations such as calcium silicate, glass fiber and to some degree cellular plastic foams will
absorb and hold liquids and vapors. Additional flashing is required where spills, leaks, drippings
or where washing and hosing are carried out. The only fully nonabsorbent insulation is cellular
glass. Cellular glass must be used where corrosive or flammable liquids are present.
Design consideration of vessels, piping including consideration of supports and connects can be
found NACE SPO198 and handbook from Midwest Insulation Contractor's Association. Based
on practical experience stand pond the reason for frequently broken of weather barriers in the
insulation either because inappropriate details were originally given for equipment during
construction or not enough space was allotted around the insulation.
To minimize the corrosion under insulation, development of design can be accomplished by
handling the insulation specifications early during the vessel design and by "simplifying" the
surface to be insulated.
Protective coating system shall protect the item for long periods against the corrosive
contaminants. Normally under insulation highly permeable coating is not advisable, because this
type of coating will lead to permeate the moisture in to the coating to start corrosion behind the
coating.
Selection of coating is a vital role to prevent the corrosion under insulation, modern days several
coatings are developed under insulation to prevent the corrosion under insulation for long
lasting like Phenolic Epoxy, Silicone Aluminum and as stated in the NACE SPO 198.
In general cyclic temperature Zinc Silicate base coating not advisable.
The coating being used under insulation has the following basic parameter , good withstanding
of temperature, the selected protective coating must with stand the design temperature, good
abrasion resistance and also the coating will with stand the good immersion property
particularly hot water immersion and corrosive- chemical immersion.
The main purpose of weather/vapor jacket of the insulation provides barrier to water. This
weather / vapor jacket is the only part of the insulation system that can be verified and inspected
quickly and repaired easy an economically.
Routine preventive maintenance is required to identify and catch defects due to deterioration or
mishandling. If the insulation system is opened in any way for maintenance or inspection activity
it should be closed promptly after work is completed. If the insulation opening was not closed
properly then heavy corrosion problem will be encounter with in a short period that to more
possible where the cyclic process service and climatic condition.
5. NIGIS * CORCON 2016 * Sept. 18 – 21, 2016 * New Delhi
Copyright 2016 by NIGIS. The material presented and the views expressed in this paper are solely those of the author(s) and do not necessarily by NIGIS.
Extensive use of a non-breathing metallic jacket is believed to contribute greatly to corrosion of
warm equipment. Without a permeable jacket, water is trapped. Water in the insulation reaches
a point where it is vaporized. Vapor travels to the jacket and condenses; the cycle repeats itself
Preventing galvanic corrosion under CUI
GC main contribution factor is results from contaminated water invasion in a wet or humid
atmosphere., Selecting cellular insulation may be the only answer. Also, Plastic or synthetic-
rubber jacket may be used to prevent engrossing of water to prevent galvanic couple. Such
special jackets are factory applied and are fire and weather resistant. This type of jackets
greatly offer protection from normal abuse and from easy penetration of water. Advantage of
plastic jacketing’s normally will not corrode. For example, chlorosulfonated polyethylene
(CSPE) synthetic rubber (CSM) resists sodium chloride solutions to 125°C (260°F)
The alternate method to minimize or inhibit the cathodic and anodic reactions by apply suitable
painting over the substrate, these protective coating are provide a highly resistive path to
current flow. However, some type pigments can promote corrosion, especially in the base coats.
Such a pigments are red oxides, gypsum, ochre, graphite and lamp black. In a corrosion
reaction, alkali is formed at the cathode; this alkaline area grows, even under paint films
pigmented with zinc or aluminum.
Selecting the coatings to stop galvanic corrosion, the following parameter to be considered.
Consideration about reversal in the polarity of galvanic couple when temperature
increases or Cyclic.
Contaminants particularly salts are carried into the insulation and placed onto surfaces
inhibit with, or abolish, the effectiveness of corrosion inhibitors
Preventing alkaline or acidic Corrosion under CUI
To prevent Chemical corrosion under the metal jacket, the metal jackets should contain
moisture barriers on the inside. As stated in the preventing galvanic corrosion the same as
plastic jacket is another option to preventing the Alkaline and Acidic corrosion problem, or
plastic weather types are a good answer.
If certain type or combination of metals cannot be avoided then painting over the substrate is a
good option. Precautions with water and the insulation cement are needed if the stainless steel
piping or equipment is being protected by insulating cement then more care to be taken with
respect to water used for insulating cement and type of insulating cement.
For underground pipes, the pipe should be painted before it is insulated, and then a coating
should be applied over the insulation. The pipe should be coated with suitable paint system or an
extruded polyethylene jacket. A polyethylene jacket should also be placed over the insulation.
6. NIGIS * CORCON 2016 * Sept. 18 – 21, 2016 * New Delhi
Copyright 2016 by NIGIS. The material presented and the views expressed in this paper are solely those of the author(s) and do not necessarily by NIGIS.
Field-made joints. Rigorous inspection methods are needed to ensure that joints are done
correctly. Internally mounted anode beneath the primary weathering barrier and above the
secondary coating has been found effective as an additional measure.
Preventing chloride Corrosion under CUI
With stainless steels, problems have been resulted due to Leachable chlorides contained in
some insulation result in severe corrosion problem. To avoid the corrosion problem
recommended to use insulation that meets ASTM C-795 specifications. This provides sufficient
control, unless there is an external invasion of chlorides. A further way to reduce the chance of
chloride attack is to use an inhibited insulation.
Other points should also be considered to prevent chloride induced corrosion:
With some insulation, such as polyurethane, it is not possible to add
inhibitors. Thus, fire-retarded polyurethanes are not recommended for use
over austenitic stainless steels.
Some specification more stringent that require less than 10 ppm of leachable
chloride in the insulation, more attention must be paid to the mortars and
cements used, since these may contain chlorides.
To prevent water and chlorides from reaching the stainless steel, the external
barrier must be designed properly and maintained periodically.
Stress – Cracking corrosion is more probable when steam tracing is used within insulation, extra
precautions are needed.
Certain type of pigment like zinc, titanium or other metallic used in the coating and applied over
stainless steel surface, lead to catastrophic embrittlement in case of any fire accident.
The metal jacketing must be securely fastened to prevent water entry at joints, or where the
insulation is supported with attachment angles.
Suitable water proof mastic is recommended over Cement-coated insulation to prevent water
ingress. The type of insulation and method of application chosen should assure the absence of
shrinkage cracks.
Prior to insulation any stainless steel equipment it is highly advisable to wrap the equipment by
aluminum foil, this foil act as a physical barrier to prevent to leach out any contaminants over
the surface particularly chloride containing solution. The aluminum will be at considerably the
same temperature as the equipment, and the chloride solution will shift to the foil, rather than
the stainless.
7. NIGIS * CORCON 2016 * Sept. 18 – 21, 2016 * New Delhi
Copyright 2016 by NIGIS. The material presented and the views expressed in this paper are solely those of the author(s) and do not necessarily by NIGIS.
Detection
Several method is currently practiced to detect the corrosion under insulation, in general the
following logics are followed
By the previous inspection history the corrosion like to occur.
API 510 recommends the process vessel to be remove at least every five year on all
vessel where there is a possibility of external corrosion.
Without removal of insulation there a several tools and techniques are used in modern current
industry practices those are
Real time Radiography
Guided wave Ultrasonic
Temperature survey
Acknowledgments
I would like to thank Sadara Management and my dear wife Unsasi Kumar, Friends and
Colleagues helped me a lot in finalizing this technical literature within the limited time frame.
References
Delahunt, J. F. "Corrosion Control under Thermal Insulation and
Fireproofing." Proceedings: Exxon Research & Engineering Co. Internal
Conference on Corrosion Under Insulation (1984): p 554.
NACE -SPO 198-2010