NACE CIP 2 Exam Questions with correct Answers

Describe passivation - ANSWER-Passivation is the formation of a protective oxide Film on the surface reducing its chemical activity and its ability to corrode Describe the following factors and how they affect corrosion - ANSWER-Oxygen: oxygen increases the rate of corrosion temperature Temperature: corrosion usually accelerated with increasing temperature Chemical salts: increase the rate of corrosion by increasing the efficiency of the electrolyte humidity: the wetter the environment, the more corrosion is likely to occur pollutants and acid gases: all promote corrosion Two broad categories of corrosion can be described as - ANSWER-General and localized Describe galvanic corrosion - ANSWER-Galvanic corrosion is an electrochemical action of two dissimilar metals in the presence of an electrolyte and an electron conductive path, Which occurs when the dissimilar metals come into contact Describe cathodic protection - ANSWER-Cathodic protection is the reduction or elimination of corrosion by making the structure to be protected a cathode by means of impressed current or attachment to a galvanic anode The two primary types of cathodic protection are - ANSWER-Impressed current and galvanic (sacrificial) impressed current power sources include: - ANSWER-1. Generators 2. Fuel cells 3. Wind powered cells 4. Thermoelectric cells 5. Rectified commercial power 6. Solar Cells Describe cathodic disbondment - ANSWER-The separation of the coating from the surface through hydroxyl formation due to increased ( made more negative ) potential. Describe dehumidification - ANSWER-Dehumidification is the process of removing moisture vapor from the air to lower its dew point When planning enclosures the following minimum requirements should be considered - ANSWER-Must be large enough to contain the whole work area. Not be larger than the performance capabilities of the dehumidification equipment. Be sturdy enough to hold up to intended work activities, potential loads, and a possible inclement weather. Have minimal leakage to maintain proper environmental conditions and ensure the dehumidification system operates efficiently. Describe air turns (air changes) - ANSWER-The air turnover principal illuminates air stratification, or layering, in large open spaces by recirculating the hot air that becomes trapped in the higher spaces. The number of times it does this per hour is called air turns. At & below what relative humidity does corrosion virtually cease - ANSWER-40% Describe two ways to reduce the relative humidity of the boundary layer - ANSWER-Increase the surface temperature and reduce moisture content by dehumidification Types of dehumidification equipment include - ANSWER-Refrigeration and desiccant Describe several benefits of dehumidification - ANSWER-Dries the air. Lowers the dew point. Permits blasting the entire surface. Holds the blast with dry air. Helps in cleaning the surface. Holds the surface during coating application. Electronic hygrometers can be used to determine - ANSWER-Relative humidity, air temperature, and dewpoint temperature. Advanced environmental testing instruments have the ability to store data that can be transferred to a computer and other devices. Transfer methods include - ANSWER-USB, IR, Bluetooth Some general basic centrifugal blast set ups include - ANSWER-Tumbling mill, multitable, plain table, swing table, custom designed systems Centrifugal blasting conveyor systems are commonly used for cleaning - ANSWER-Plate, rolled structural shapes, large trusses, girders Portable centrifugal blasting systems can be used on - ANSWER-Ship decks, hull sides, and bottoms. Storage tanks. Concrete floors. Highways and bridge decks. Generally centrifugal blast systems are composed of the following elements - ANSWER-Centrifugal abrasive throwing wheel, the blast cabinet, in fixed systems some type of material handling system, abrasive recycling system, a dust collector and vent pipe system, abrasives. The efficiency of the centrifugal blast wheels depends on several factors - ANSWER-Abrasive operating mix, size of the abrasive, velocity of the abrasive coming off the wheel, quantity and direction of the thrown abrasive, condition of the feed parts. Little amperage readings on a centrifugal blasting machine could signify - ANSWER-An abrasive starved wheel, a flooded or choked wheel The functions of the centrifugal blasting machine separator include - ANSWER-To control the sizing of the abrasive mix, to remove sand, spent abrasives, rust, dirt, and any other contaminants from the abrasive stream, to control abrasive consumption A well balanced operating mix (working mix) of abrasives will - ANSWER-Provide consistency of the finish, ensure uniform abrasive coverage, ensure conditioning of the abrasive for optimum cleaning, minimize lowest abrasive and machine part where and reduce downtime for maintenance Some of the inspection concerns during centrifugal blasting include - ANSWER-Monitor the dust collector, monitor the amperage of the wheel motors / low amperage, Monitor the handling in the loading of the conveyor line for contaminants and possible discontinuities in the steel, monitor the speed of wine, inspect the steel as it leaves the production line The WJ-1 (visual cleanliness) is comparable to which abrasive blast cleaning standard - ANSWER-ISO SA 3 A general description of robotic water jetting includes - ANSWER-Attaches using vacuum, cables, or magnets Vertical, Horizontal or overhead surface Controlled by single operator Collects in excess 95% of the water, removed coatings and rust (waste generated) A typical waterjetting team consist of - ANSWER-The nozzle operator, the pump operator, additional operators or workers. Waterjetting is effective for removing - ANSWER-Surface oil and grease, rust, concrete (shot-crete) spatter, existing coatings, water soluble contaminants that cannot otherwise be removed by abrasive blasting, an underwater unit used to clean barnacles or other microorganisms for ships hulls or offshore platform legs. Describe two of the considerations with regards to "back thrust" - ANSWER-Causes fatigue and should 1/3 of operators body weight To ensure safe workplace, before commencing the job, the waterjet team should ensure that - ANSWER-The work area is properly barricaded. Electrical equipment is protected from water. Electrical connections are not allowed to sit in water. All fittings and hoses are in good condition / proper pressure rating. Nozzle is free of obstructions. System is flushed clean and air removed. The dump system and all control systems are operational. Proper LOTO provisions / confined space entry requirements. Waterjetting advantages include - ANSWER-Worker safety Worker air quality Respiratory requirements may be less stringent No dust contamination or clean up Friendly to the environment Relatively cost efficient It requires less cleaning Disadvantages of waterjetting include - ANSWER-Leaves no profile Equipment is very expensive Danger of UHP hose breaking Danger of injection into skin or serious cuts Collecting and disposing of the contaminated water Proficient operator Some of the most common hazards associated with specialized application are - ANSWER-Fumes and dust inhalation Electrical shocks Burns Falling objects Explosions Environmental contamination Thermal spray safety practices for operators include - ANSWER-Use hoses rated for high pressure Never clean powder off equipment or clean spray cubicles with compressed air Do not use compressed air to clean off clothing Do not supply plant compressed air to breathing apparatuses Reduce compressed air to less than 30 pounds per square inch for cleaning purpose In the coating industry a lining is described as - ANSWER-A coating that is used in an immersion surface Some common resins used in reinforced linings include - ANSWER-Polyester Epoxy Vinyl Ester What is the main feature that reinforcing adds to a resin? - ANSWER-Strength Describe wicking and how it may negatively affect a coating system? - ANSWER-The negative effect reinforcing has on a resin is the ability of a liquid to travel along the fibers path (wicking) and cause Corrosion to the substrate, blisters, or delamination of the system. Describe normal surface preparation requirements for installation of a lining - ANSWER-With a lining the normal requirement for surface preparation for new surfaces is cleaning in accordance to SA3/NACE1/SSPC5 White Metal Blast Cleaning. You may see the requirement for SA2.5/NACE2/SSPC10 Near White Metal Blast Cleaning when performing maintenance work. Waterjetting is only used for lining work when a surface profile already exists. However you may see a requirement to water wash or jet to remove soluble contaminants and then abrasive blast. In some cases you may find it necessary to abrasive blast a surface then wash it and blast again. This could be repeated several times before an acceptable result is achieved. What are antifouling materials used for, and how do they work? - ANSWER-The purpose of antifouling (AF) paints is to either make the hull of the ship so distasteful the larva of the biofouling rejects it as home or they make the hull so slick the larva can't adhere. The three main types of anti fouling coatings are - ANSWER-Ablative Self smoothing Foul release Types of fireproofing coating - ANSWER-Cementitious- made of lightweight cement and can be applied several inches thick. Intumescent- a substance that swells or bubbles up as a result of heat exposure, thus increasing in volume, and decreasing in density. What are the best known characteristics of fluoropolymer coatings - ANSWER-Flouropolymer coatings are best known for their non stick feature and also have excellent chemical and high temperature resistance. Describe the two broad curing categories of powder coatings - ANSWER-Thermoplastic- materials that soften when heated and return to their original hardness when cooled. Thermosetting- materials that harden when heated and retain their hardness when cooled. What are the four distinct stages powders pass through when a heat source is applied? - ANSWER-The flow stage- which occurs when the particles of powder begin to flow, but are not fully liquid Wetting stage- which occurs when the particles of powder absorb more heat, fully liquefy, and wet the surface Gel stage- which occurs when the particles of the powder begin to gel, converting into a solid Curing stage- allows for further changes to take place, permitting the powder to cure properly Advantages and disadvantages of plural component airless spray over single piston airless spray systems - ANSWER-Advantages: Accurate mixing of materials without human element Ability to spray very thick solvent free materials without thinner The ability to spray materials with very short pot life Disadvantages: Cost is much higher than cost of single piston pump Higher education requirement for the Mechanic High voltage electricity is required for the heaters Applicators job more difficult with multiple hoses 2 major classes of rubber - ANSWER-Natural- derived from latex obtained from Hevea trees and is coagulated with acetic or formic acid. Unsaturated hydrocarbon known as polyisoprene Synthetic- any one of a group of man made elastomers with one or more of the properties of natural rubber. Vulcanization - ANSWER-Vulcanization is a physicochemical (physical and chemical) change resulting from the cross linking of the unsaturated hydrocarbon chain of natural rubber (polyisoprene) with sulfur, and the application of heat. Three factors that affect the properties of the vulcanizate (vulcanized product) - ANSWER-Percentage of sulphur and accelerator used Temperature of the curing process Time of cure Methods used to cure (vulcanize) rubber are - ANSWER-Autoclave (vulcanizer) cure Internal steam cure Atmospheric steam cure (also called exhaust steam cure) Hot water cure Chemical cure The three categories of natural rubber are - ANSWER-Soft, semi hard, hard What is a tri-ply lining - ANSWER-Lining construction used to form a sandwich which is semi-hard, or hard, rubber between two layers of soft rubber Some various types of synthetic rubber are - ANSWER-Butyl rubber Neoprene rubber Nitrile rubber Chlorobutyl rubber Hypalon types Typical surface preparation requirements (rubbers) - ANSWER-1. Steel shall be new, full weight steel, free from structural defects 2. Steel plate shall be flat with no appreciable warp or buckle 3. Steel plate should have a minimum thickness and weight specified 4. Vessel must be braced to avoid bulging 5. All welds to be continuous, peened, and ground to remove sharp edges and high spots. 6. Edges and corners should be ground to a minimum radius as specified 7. All weld spatter should be removed 8. Blast cleaned to NACE 1 with surface profile of 1.5-2.5 mils Some of the causes of failure with rubber linings may be - ANSWER-Incorrect product selected for the intended service Using rubber after the shelf life has expired Using rubber l