3rd Class Power Engineering - B1 - Part
3 with verified solutions rated A+
What are 'Toe Cracks' in welds? - correct answer ✔✔- Occur when the face of the weld terminates at the
surface of the parent metal
- Thermal stresses are very high at this point and cracking often occurs in a direction normal to the
parent
What is 'Underbead Cracking' as a welding defect? - correct answer ✔✔- Occurs in either the weld or the
heat affected zone
Lamellar Tears? - correct answer ✔✔- Cracks that occur due to high restraint and high residual stress
- They appear on the interface of the weld and the base metal, or completely in the base metal
Planar type defects, such as cracks and lack of fusion, pose high risk for metal failure. Pores and non-
metallic inclusions on the other hand, are rounded and pose less of a potential for failure. True or False?
- correct answer ✔✔True.
What are the 3 types of defects that NDE testing is used for in the pressure equipment industry? -
correct answer ✔✔1) Inherent defects: defects that are created during the initial production of the
material
2) Processing Defects: defects created in the metal during the construction of the pressure equipment
3) Service Defects: defects created during the service of the equipment
4 most common types of NDE testing? - correct answer ✔✔- Liquid Penetrate Testing
- Magnetic Particle Testing
- Radiographic Testing
- Ultrasonic Testing
,What is a prerequisite for a material to be tested using Liquid Penetrate testing? - correct answer ✔✔-
Flaws must be open to the surface
- The examined surface cannot be rough or porous, since these conditions interfere with the PT
inspection
What is Capillary Action, and how does it relate to Dye Penetrate testing? - correct answer ✔✔-
Cohesive forces between the liquid and the straw are greater than the cohesive forces within the liquid
itself
Other than Capillary Action, what is another principle that affects Penetrate Testing? - correct answer
✔✔- The ability of the liquid to migrate and wet over the surface of the material
- Migration depends on the surface tension and contact angle of the material
The liquid penetrant must not only be able to penetrate the material, but also withdraw from the
material after inspection. True or False? - correct answer ✔✔True
4 types of possible materials Liquid Penetrant testing works for? - correct answer ✔✔Materials that are
welded, cast, rolled or forged
In brief, list the 6 major steps in Liquid Penetrant Testing. - correct answer ✔✔1) Pre Cleaning
2) Penetrant application
3) Excess Penetrant Removal
4) Developer Action
5) Inspection/Interpretation
6) Post-Cleaning
Cleaning surfaces before Liquid Penetrant Testing? - correct answer ✔✔- Use solvents or degreases to
remove any contaminants
2 means of applying Penetrant (dye)? - correct answer ✔✔Spraying or Brushing
Visible Penetrants? - correct answer ✔✔- Defects can be seen using normal incandescent light
, Fluorescent Penetrants? - correct answer ✔✔- Require ultraviolet light to see the defects
Removing Excess Penetrant? - correct answer ✔✔A solvent or water is used to remove excess penetrant
from the surface, leaving penetrant in the defects only
Developer Action in LP testing? - correct answer ✔✔- A developer is a chemical that draws the penetrant
out of the defects and reacts with the penetrant to produce an outline of the defect
- Developer is sprayed onto the surface forming a consistent, even coating
Post Cleaning after LP testing? - correct answer ✔✔- Clean penetrant and developer of the test material
being careful not to remove any defect markings
Magnetic Particle Testing? - correct answer ✔✔- NDE technique that detects surface or sub-surface flaws
- Can only be applied to ferromagnetic materials
Working principle behind Magnetic Particle Testing? - correct answer ✔✔- Magnetic flux in a material is
distorted by any defects
- Distortion is greatest when the defect is perpendicular to the magnetic field
- A pair of magnetic poles, which act as magnets, are created if the distortion of the magnetic field is
great enough
What is the purpose of the magnetic particles in MT? - correct answer ✔✔- Magnetic particles are
attracted to the poles created in the defective surface, indicating the location of the defect
- Magnetic particles either come Wet or Dry, and in various colours to aid in distinction
Magnetic Particle Testing can be used on ferromagnetic pressure components that are welded, cast,
rolled or forged, and typical defects found are Lack of Penetration and Cracks. True or False? - correct
answer ✔✔True.
6 general steps to Magnetic Particle Testing? - correct answer ✔✔1) Pre-cleaning the surface
2) Magnetizing the component
3 with verified solutions rated A+
What are 'Toe Cracks' in welds? - correct answer ✔✔- Occur when the face of the weld terminates at the
surface of the parent metal
- Thermal stresses are very high at this point and cracking often occurs in a direction normal to the
parent
What is 'Underbead Cracking' as a welding defect? - correct answer ✔✔- Occurs in either the weld or the
heat affected zone
Lamellar Tears? - correct answer ✔✔- Cracks that occur due to high restraint and high residual stress
- They appear on the interface of the weld and the base metal, or completely in the base metal
Planar type defects, such as cracks and lack of fusion, pose high risk for metal failure. Pores and non-
metallic inclusions on the other hand, are rounded and pose less of a potential for failure. True or False?
- correct answer ✔✔True.
What are the 3 types of defects that NDE testing is used for in the pressure equipment industry? -
correct answer ✔✔1) Inherent defects: defects that are created during the initial production of the
material
2) Processing Defects: defects created in the metal during the construction of the pressure equipment
3) Service Defects: defects created during the service of the equipment
4 most common types of NDE testing? - correct answer ✔✔- Liquid Penetrate Testing
- Magnetic Particle Testing
- Radiographic Testing
- Ultrasonic Testing
,What is a prerequisite for a material to be tested using Liquid Penetrate testing? - correct answer ✔✔-
Flaws must be open to the surface
- The examined surface cannot be rough or porous, since these conditions interfere with the PT
inspection
What is Capillary Action, and how does it relate to Dye Penetrate testing? - correct answer ✔✔-
Cohesive forces between the liquid and the straw are greater than the cohesive forces within the liquid
itself
Other than Capillary Action, what is another principle that affects Penetrate Testing? - correct answer
✔✔- The ability of the liquid to migrate and wet over the surface of the material
- Migration depends on the surface tension and contact angle of the material
The liquid penetrant must not only be able to penetrate the material, but also withdraw from the
material after inspection. True or False? - correct answer ✔✔True
4 types of possible materials Liquid Penetrant testing works for? - correct answer ✔✔Materials that are
welded, cast, rolled or forged
In brief, list the 6 major steps in Liquid Penetrant Testing. - correct answer ✔✔1) Pre Cleaning
2) Penetrant application
3) Excess Penetrant Removal
4) Developer Action
5) Inspection/Interpretation
6) Post-Cleaning
Cleaning surfaces before Liquid Penetrant Testing? - correct answer ✔✔- Use solvents or degreases to
remove any contaminants
2 means of applying Penetrant (dye)? - correct answer ✔✔Spraying or Brushing
Visible Penetrants? - correct answer ✔✔- Defects can be seen using normal incandescent light
, Fluorescent Penetrants? - correct answer ✔✔- Require ultraviolet light to see the defects
Removing Excess Penetrant? - correct answer ✔✔A solvent or water is used to remove excess penetrant
from the surface, leaving penetrant in the defects only
Developer Action in LP testing? - correct answer ✔✔- A developer is a chemical that draws the penetrant
out of the defects and reacts with the penetrant to produce an outline of the defect
- Developer is sprayed onto the surface forming a consistent, even coating
Post Cleaning after LP testing? - correct answer ✔✔- Clean penetrant and developer of the test material
being careful not to remove any defect markings
Magnetic Particle Testing? - correct answer ✔✔- NDE technique that detects surface or sub-surface flaws
- Can only be applied to ferromagnetic materials
Working principle behind Magnetic Particle Testing? - correct answer ✔✔- Magnetic flux in a material is
distorted by any defects
- Distortion is greatest when the defect is perpendicular to the magnetic field
- A pair of magnetic poles, which act as magnets, are created if the distortion of the magnetic field is
great enough
What is the purpose of the magnetic particles in MT? - correct answer ✔✔- Magnetic particles are
attracted to the poles created in the defective surface, indicating the location of the defect
- Magnetic particles either come Wet or Dry, and in various colours to aid in distinction
Magnetic Particle Testing can be used on ferromagnetic pressure components that are welded, cast,
rolled or forged, and typical defects found are Lack of Penetration and Cracks. True or False? - correct
answer ✔✔True.
6 general steps to Magnetic Particle Testing? - correct answer ✔✔1) Pre-cleaning the surface
2) Magnetizing the component
