NACOR ACTUAL TEST QUESTIONS WITH
COMPLETE SOLUTION PREMIUM REVIEW
CONTENT
●● 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.
COMPLETE SOLUTION PREMIUM REVIEW
CONTENT
●● 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.
