CWB LEVEL 2 UPDATED 2026 EXAM SCRIPT QUESTIONS
AND ANSWERS GRADED A+
✔✔What is the appearance of damage for Erosion, Erosion-Corrosion? - ✔✔Localized
loss in thickness in the form of pits, grooves, gullies, waves, rounded holes or valleys.
These often exhibit a directional pattern.
✔✔What are some ways of prevention/Mitigation for Erosion, Corrosion-Erosion? - ✔✔-
Improvement in design. Involving *shape, geometry, material selection
-Improvement of resistance achieved through increasing substrate hardness using
harder alloys, hard-facing or surface-hardening treatments.
-Heat ex changers utilize impingement plates and occasionally tube ferrules to minimize
erosion
✔✔What is used to detect refractory loss on stream when erosion is suspected? - ✔✔IR
scan
✔✔What are 3 ways to inspect an area of erosion - ✔✔Visual
UT checks
RT to check extent of metal loss
✔✔What is the description of Mechanical Fatigue? - ✔✔Mechanical fatigue is a form of
degradation that occurs when a component is exposed to cyclical stresses for an
extended period, often resulting in sudden unexpected failure.
✔✔What type of material is subject to Mechanical fatigue? - ✔✔All engineering alloys
are subject to fatigue cracking
✔✔What are the predominant factors in determining the fatigue resistance of a
component? - ✔✔Geometry, Stress Level, Number of cycles and material properties (
strength, hardness, micro-structure)
✔✔With mechanical fatigue where do fatigue cracks usually initiate? - ✔✔Surface of
mechanical notches, stress raisers under cyclic loading, Weld joints, tool markings,
grinding marks, corrosion areas, key holes on drive shafts
✔✔With what 3 types of material does fatigue fractures decrease with stress amplitude
until an endurance limit is reached? Regardless of the number of cycles - ✔✔Titanium,
Carbon Steel, and Low Alloy Steel.
✔✔What are some affected units/equipment from mechanical fatigue? - ✔✔Thermal
Cycling;
*Equipment that cycles daily like coke drums
, *Equipment that is on continuous standby but sees intermittent service such as auxiliary
boilers.
*Quench nozzle connections that sees significant temperature deltas during operation
like a water washing system.
Mechancial Loading ;
*Pressure swing Absorbers on hydrogen purification units
*Rotating shafts on centrifugal pumps and compressors that have stress concentrations
dur to changes in radii and key ways
*Components like small diameter piping that may see vibration from adjacent equipment
and/or wind.
*High pressure drop control valves or steam reducing stations can cause serious
vibration problems in connecting piping.
✔✔What is the appearance of mechanical fatigue damage? - ✔✔The signature mark for
fatigue failure is a clam shell type fingerprint.
✔✔What can you do to prevent mechanical fatigue? - ✔✔*Best defense against fatigue
cracking is good design.
*Selecting a metal with a design fatigue life sufficient for its intended cyclic service
*Allowing for generous radius along edges and corners
✔✔How do you inspect for mechanical fatigue cracks? - ✔✔NDE techniques such as
PT,MT, and SWUT
✔✔How would you inspect small diameter piping to detect oscillation or other cyclical
movement that could lead to cracking? - ✔✔VT
✔✔Define Galvanic Corrosion? - ✔✔Form of corrosion that can occur at the junction of
dissimilar metals when they are joined together in a suitable electrolyte, such as a moist
or aqueous environment, or soil containing moisture.
✔✔What kind of material is affected by galvanic corrosion? - ✔✔All Metals with the
exception of most noble metals
✔✔What are 3 critical factors that must be met for galvanic corrosion? - ✔✔1)Presence
of an electrolyte, a fluid that can conduct a current. Moisture or a separate water phase
is usually required for a solution to have enough conductivity.
2) 2 different materials or alloys known as the anode and the cathode, in contact with an
electrolyte.
3) An electrical connection must exist between the anode and the cathode.
✔✔What units/equipment does galvanic corrosion affect? - ✔✔*Galvanic Corrosion can
occur in any unit where there is a conductive fluid and alloys are coupled.
AND ANSWERS GRADED A+
✔✔What is the appearance of damage for Erosion, Erosion-Corrosion? - ✔✔Localized
loss in thickness in the form of pits, grooves, gullies, waves, rounded holes or valleys.
These often exhibit a directional pattern.
✔✔What are some ways of prevention/Mitigation for Erosion, Corrosion-Erosion? - ✔✔-
Improvement in design. Involving *shape, geometry, material selection
-Improvement of resistance achieved through increasing substrate hardness using
harder alloys, hard-facing or surface-hardening treatments.
-Heat ex changers utilize impingement plates and occasionally tube ferrules to minimize
erosion
✔✔What is used to detect refractory loss on stream when erosion is suspected? - ✔✔IR
scan
✔✔What are 3 ways to inspect an area of erosion - ✔✔Visual
UT checks
RT to check extent of metal loss
✔✔What is the description of Mechanical Fatigue? - ✔✔Mechanical fatigue is a form of
degradation that occurs when a component is exposed to cyclical stresses for an
extended period, often resulting in sudden unexpected failure.
✔✔What type of material is subject to Mechanical fatigue? - ✔✔All engineering alloys
are subject to fatigue cracking
✔✔What are the predominant factors in determining the fatigue resistance of a
component? - ✔✔Geometry, Stress Level, Number of cycles and material properties (
strength, hardness, micro-structure)
✔✔With mechanical fatigue where do fatigue cracks usually initiate? - ✔✔Surface of
mechanical notches, stress raisers under cyclic loading, Weld joints, tool markings,
grinding marks, corrosion areas, key holes on drive shafts
✔✔With what 3 types of material does fatigue fractures decrease with stress amplitude
until an endurance limit is reached? Regardless of the number of cycles - ✔✔Titanium,
Carbon Steel, and Low Alloy Steel.
✔✔What are some affected units/equipment from mechanical fatigue? - ✔✔Thermal
Cycling;
*Equipment that cycles daily like coke drums
, *Equipment that is on continuous standby but sees intermittent service such as auxiliary
boilers.
*Quench nozzle connections that sees significant temperature deltas during operation
like a water washing system.
Mechancial Loading ;
*Pressure swing Absorbers on hydrogen purification units
*Rotating shafts on centrifugal pumps and compressors that have stress concentrations
dur to changes in radii and key ways
*Components like small diameter piping that may see vibration from adjacent equipment
and/or wind.
*High pressure drop control valves or steam reducing stations can cause serious
vibration problems in connecting piping.
✔✔What is the appearance of mechanical fatigue damage? - ✔✔The signature mark for
fatigue failure is a clam shell type fingerprint.
✔✔What can you do to prevent mechanical fatigue? - ✔✔*Best defense against fatigue
cracking is good design.
*Selecting a metal with a design fatigue life sufficient for its intended cyclic service
*Allowing for generous radius along edges and corners
✔✔How do you inspect for mechanical fatigue cracks? - ✔✔NDE techniques such as
PT,MT, and SWUT
✔✔How would you inspect small diameter piping to detect oscillation or other cyclical
movement that could lead to cracking? - ✔✔VT
✔✔Define Galvanic Corrosion? - ✔✔Form of corrosion that can occur at the junction of
dissimilar metals when they are joined together in a suitable electrolyte, such as a moist
or aqueous environment, or soil containing moisture.
✔✔What kind of material is affected by galvanic corrosion? - ✔✔All Metals with the
exception of most noble metals
✔✔What are 3 critical factors that must be met for galvanic corrosion? - ✔✔1)Presence
of an electrolyte, a fluid that can conduct a current. Moisture or a separate water phase
is usually required for a solution to have enough conductivity.
2) 2 different materials or alloys known as the anode and the cathode, in contact with an
electrolyte.
3) An electrical connection must exist between the anode and the cathode.
✔✔What units/equipment does galvanic corrosion affect? - ✔✔*Galvanic Corrosion can
occur in any unit where there is a conductive fluid and alloys are coupled.
