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3.2u Refresher updated Jan 2024 > 3.2u Mixed papers 2 (old) > Flashcards

3.2u Mixed papers 2 (old) Flashcards

1
Q

HP water jet finishing on painted steel structure

(Question not clear, I dont have copies of this test paper anymore)

A

SA3

3.4u Manual

Paints
When paint is applied to a metal surface it presents a barrier to air, moisture and ions aggressive to the metal. However, paint cannot provide a complete barrier to oxygen or water. In time these will penetrate through to the surface of the metal. Any paint system used underwater must have a strong bond onto the metal surface and therefore high quality metal surface preparation is required such as SA3. The bonding between successive coats must also be strong and the topcoats must provide as impervious a barrier to the electrolyte as is possible.

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2
Q

Before CP survey, Bathycorrometer should be

A

Answer: All of the above

A. Tested in fresh seawater
B. Tested on zinc block and unprotected steel
C. Tested at Depth
D. All of the above

Answer is D

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3
Q

Prior to MPI inspection, checking a permanent magnet will lift 18kg serves what purpose?

A

Checking that it has sufficient power to induce the field strength and meets the required standard

Magnetising Equipment: BS EN 9934-1
1 Tesla magnetising force required

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4
Q

The efficiency of a cathodic protection system can be assessed by

A

Taking readings of the electrical potential

Over-protected structure : More negative than -1100mV Zinc: -1050 mV
Protected steel: -800 to -11—mV
Under protected steel: -640 to -800mV
Unprotected steel: -450 to-640mV
Monel: -50 to-150mV

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5
Q

If aluminium is connected to mild steel and immersed in seawater, the aluminium will be

A

The anode

Galvanic Series: think of it as a superhero team where some metals are strong and don’t get hurt (noble), and others are weaker and get damaged (corrode) when facing a villain (the liquid).

Galvanic Series in seawater.
Graphite
Gold
Platinum
Silver
Stainless steel
Monel
Copper
Niobium
Tungsten
Lead
Cast iron
Mild steel
Aluminium
Zinc
Magnesium

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6
Q

On the pH scale which of the following values would be described as acidic

A

pH2.5

Therefore, any value less than 7 would be described as acidic. The lower the pH value, the more acidic the substance is. Neutral substances have a pH of 7, while values above 7 are considered alkaline or basic.

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7
Q

An ion is atom that has a positive , negative or both?

A

Has a positive or negative charge

https://youtu.be/EIAaGHK5pjA?si=euKYfYEWKOLgpWD3

An ion is an atom or molecule that has gained or lost electrons, giving it a net positive or negative electric charge. If it has more protons than electrons, it’s a positive ion or cation. If it has more electrons than protons, it’s a negative ion or anion

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8
Q

The Pourbaix diagram displays 2 sets of data?

A

Electrode potential and pH value

There are numerous methods for preventing corrosion including, coatings, inhibitors (controlling the electrolyte), selective design, anodic protection and cathodic protection. Before considering these methods a brief examination of the way in which the corrosion process is influenced by the two main variables; the electrode potential and the pH value will assist in understanding the various protection methods.

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9
Q

A structure protected by an ICCP system identifies a shadow area….what could be done to improve that protection for that area

A

Install sacrificial anode

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10
Q

Offshore structures use impressed current systems in preference to sacrificial systems because they

A

Reduce overall weight loading

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11
Q

A calomel cell selected from a pair to be used for calibrating a CP meter, should give what reading on a voltmeter

A

+-2mv

3.4u manual: Calibration Checking between calomel cells. Acceptable readings between any pair of electrodes is +/- 2mV

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12
Q

ICCP systems use voltage/amperage values in which range?

A

30-80 volts DC / 300- 1000 amps

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13
Q

If a keeper plate was attached to a permanent magnet, which way would the flux lines run through the keeper plate

A

North to South

Here’s a simplified representation of the magnetic flux lines:

North Pole (N) → Keeper Plate → South Pole (S)

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14
Q

When lines of magnetic force jump the gap formed by a surface-breaking defect, it is called

A

Flux leakage

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15
Q

The symbol used for magnetizing force is?

A

H

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16
Q

At the coercive point on a B/H curve, the material would:

A

Have zero flux density

https://youtu.be/ZyVSMfSgOq0?si=Y4ZVd1J8rkAm7C5p

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17
Q

What can be used to protect a steel structure against corrosion in the splash zone

A

Protective coatings

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18
Q

If an atom loses one or more electrons, this will be called

A

An anodic reaction

https://youtu.be/ZyVSMfSgOq0?si=P1te2lJ1YiV0_RzC

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19
Q

In ultrasonics, frequency is measured in ?

A

Hertz

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20
Q

In regard to digital cameras, what do the initials CCD sand?

A

Charge Coupled Device

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21
Q

Before use; a Bathycorromter should be soaked for

A

30 minutes in fresh seawater

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22
Q

What is the formula to calculate the near zone?

A

NZ=D² / 4λ

lambda λ = wavelength of any wave.

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23
Q

Post-tensioning cables are used to put concrete under which sort of stress?

A

Compression

Post-tensioning cables are used to put concrete under compressive stress. This technique is employed to reinforce concrete structures by introducing compressive stress to counteract the tensile forces that the structure may experience during its lifespan1. The process involves applying controlled forces to prestressed cables or tendons, which are then anchored to the concrete, resulting in increased load-bearing capacity, improved resistance to cracking, and enhanced structural performance

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24
Q

In a single V butt weld the angle between the two prepare faces is called

A

The included angle

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25
Q

Fatigue can be described as?

A

Cyclic loading and unloading on a material causing local hardening

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26
Q

What is the minimum cover required over the Steel reinforcement in a concrete structure

A

60mm

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27
Q

What NDT method can be used to find and size for depth of a surface breaking defect in a steel structure

A

ACFM

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28
Q

The following is a true statement with regards to digital thickness meter

A

It can only show the depth to a major reflector

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29
Q

A mid-water arch is a device that is used to

A

Prevent tension in a flexible riser

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30
Q

The fundamental purpose of monel cladding is to

A

Insulate the structure from electrolyte

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31
Q

A fatigue crack will mostly be found where?

A

In the toe of the weld

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32
Q

How many mega pixels is the minimum number required for a digital camera used in underwater photography?

A

6 Mega pixels

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33
Q

In a corrosion circuit, which of the following travels through the material from anode to cathode?

A

Negative Electron

Here’s a simplified representation of the process:

Anode (site of oxidation) → Electrons travel through material → Cathode (site of reduction)

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34
Q

The corrosion that occurs beneath a water drop on a steel plate is what type?

A

Pitting corrosion

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35
Q

A method of welding that cannot be conducted on a nodal joint is?

A

Submerged arc welding

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36
Q

Which of the following is classed as a planar defect?

A

Lamination

A planar defect in metal is a type of imperfection that occurs across a plane within the crystalline structure of the material. These defects are two-dimensional and typically separate regions of the material that have different crystal structures or orientations.

A lamination defect in metal is a type of planar defect that consists of flat and thin subsurface separations inside a metal plate, parallel to the surface of the plate. This defect is considered a serious discontinuity that can originate during hot or cold forming processes

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37
Q

If a steel pipe which had an electrical potential of -520mV was placed in an electrolyte with a pH of 11.5 what would happen to it?

A

It would not corrode due to passivation

Rfere to the Pourrbaix diagram

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38
Q

In an ICCP system, the structure is the?

A

A cathode and negative

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39
Q

Which of the following statements describes the term Coercivity?

A

The amount of magnetizing force in the opposite direction required to bring the flux density to zero.

https://youtu.be/ZyVSMfSgOq0?si=DKf1af66sQVt8z61

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40
Q

When conducting an MPI inspection using an electromagnetic yoke,what is the extent of the valid inspection area?

A

Half the distance either side of the pole seperation.

Electromagnets produce a longitudinal field with the test area being a circle inscribed by the poles. Defect orientation is the same as when using a permanent magnet. BS EN ISO 9934-1 states that a lift test should be carried out prior to using for MPI. The lift test should confirm that the electromagnet can lift 4.5kg with a pole spacing of up to 300mm.

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41
Q

In mercury vapour lamps a Woods Filter is used to prevent which of the following getting through?

A

UVB wavelengths

Remeber: UVB: B for Bad…so UVA is better (safer)

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42
Q

The wavelength of a UV light used to view MPI indications is?

A

365-400nm

Light BS EN ISO 3059
Day / Black Ink / 500 lux
Night / fluorescent /20 Lux
UV 1000 μW / cm2 @ 365-400nm wavelength

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43
Q

Which of the following would require the most lines of flux if all were subjected to the same amount of magnetizing force?

A

Nickel

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44
Q

Magnetic flux lines travelling from steel into iron would do what?

A

Gather closer together

Magnetic flux lines represent the strength and direction of a magnetic field. When they travel from steel into iron, they gather closer together because iron has a higher magnetic permeability compared to steel. This means iron can more easily support the development of a magnetic field within itself. As a result, the magnetic field lines are denser or more concentrated in iron, indicating a stronger magnetic field in that region

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45
Q

The type of magentism produced by a horseshoe magnet is?

A

Longitudinal

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46
Q

The volume of a settlement flask sample for MPI ink is?

A

100ml

Ink BS EN ISO 9934-2
Settlement / Suntherland = 100ml / 60 min
Ferrous Oxide 0.1% - 0.3% by volume
Additives no more than 10% by weight

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47
Q

Which of the following statements concerning magnetic lines of flux is correct?

A

The lines all have the same strenght

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48
Q

In an ICCP system, what does a dielectric shield prevent?

A

High density current flowing directly into the structure

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49
Q

During an MPI inspection of a nodal weld using AC yoke, which of the following would not be detected?

A

A lamination running parallel to the weld

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50
Q

In an ICCP system, what is a shadow area?

A

An area of inadequate cathodic protection

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51
Q

By multiplying the RMS figure by 1.414, the sum will be the value of?

A

The peak current AC

Multiplying the RMS (Root Mean Square) value by 1.414 (which is the square root of 2) gives you the peak value of an alternating current.

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52
Q

Which of the following is an advantage of a single crystal probe over a twin crystal probe?

A

Greater penetration

Single Crystal probe:
Advantages:
Good Power Output
Greater Penetration
Disadvantages:
Poor near zone resolution
Cannot measure thin plate

Twin Crystal Probe
Advantages
Good near zone
Measure thin plate
Disadvantages
Less Power Output
Less penetration

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53
Q

The corrosion rate of an unprotected steel structure in seawater will increase if?

A

The water temperature increases

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54
Q

An offshore structure that is supported on the seabed by its own weight is termed?

A

A gravity structure

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55
Q

On a jacket, which of the following best describes the term batter?

A

The angle of the legs to the vertical

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56
Q

Vortex shedding causes what type of defect?

A

Scour

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57
Q

Which of the following items would not be required to conduct a CVI of a nodal weld?

A

A flux indicator

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58
Q

Altering the frequency of an ultrasonic probe will affect which of the following parameters?

A

The wavelenght

Yes, altering the frequency of an ultrasonic probe will affect the wavelength. The relationship between frequency and wavelength is inversely proportional, meaning that as the frequency increases, the wavelength decreases, and vice versa.

When you flick a long ruler hanging off a desk, it vibrates slowly (low frequency, long wavelength). A short ruler flicked the same way vibrates quickly (high frequency, short wavelength).

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59
Q

With regards to inspecting concrete structures; variable cover is what kind of defect?

A

A Category, a construction defect

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60
Q

Dynamic loading is based on?

A

Normal wave and wind spectrum

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61
Q

0.5 to 1.5MHz ultrasonic probes are used for testing which of the following?

A

Concrete and cast iron

62
Q

Which of these techniques cannot be used to determine the depth of a surface-breaking defect

A

Eddy Current

63
Q

In a digital camera what is a CCD

A

An image sensor

A CCD, or Charge-Coupled Device, is an electronic sensor used in digital cameras to capture light and convert it into digital signals.

64
Q

Which action does the shutter speed control

A

How long the aperture is open

65
Q

What is backscatter ?

A

Light reflecting from particles in the water

66
Q

Why would a photo mosaic be completed?

A

If access is restricted for any other method

67
Q

What is a picture grab?

A

A still taken from video

68
Q

Which of the following affects the field of view?

A

Focal lenght

69
Q

Welding joins metal together by?

A

Electro chemical reaction

70
Q

Typically how many joint configurations are seen on offshore structures?

A

2

2 (check)

71
Q

Where is the HAZ to be found?

A

In the parent plate adjacent to adjacent to the weld

72
Q

What will Hydrogen diffusing into the parent plate cause?

A

Embrittlement

73
Q

Cracks in welds are ?

A

2 dimensional

Cracks in welds are typically considered two-dimensional (2D) defects because they manifest along a plane or surface. Unlike volumetric defects, such as porosity or inclusions, which extend into the material in three dimensions, cracks are more confined to a specific plane within the weld.

74
Q

A stray flash is also known as ?

A

Arc strike

75
Q

The angle of incidence is……….?

A

Equal to the angle of reflection

76
Q

What should be reported when carrying out an anode inspection?

A

Anode size

77
Q

What would cause spurious indication in MPI?

A

Answer: Dirt or scale
a. Grinding mark
b. Dirt or scale
c. Toe undercut
d. Poor cap profile

78
Q

Another name for preferential corrosion is

A

Weld decay

Weld decay or preferential corrosion is an example of this type of decay. In this case the boundary is the fusion boundary that forms along the toe of the weld and is a region of higher energy. This region becomes the
anode and corrosion sets in, often giving quite significant visual indications of its presence.

79
Q

In Photography: What can produce a narrower field of view

A

Increase the focal length of the lens

In photography, using a lens with a longer focal length will produce a narrower field of view. A longer focal length lens magnifies the image and captures a smaller portion of the scene, resulting in a more zoomed-in or telephoto view.

80
Q

Iridium 192 is a gamma radiation source for

A

Weld inspection of plate up to 50mm

81
Q

Assuming you have access to both sides of a weld, which of the following defects could not be found during a visual inspection?

A

Answer: Lack of inter-run fusion in a single V butt weld

a. Lack of inter-run fusion in a single V butt weld
b. Lack of root penetration in a single bevel butt weld
c. Lack of root penetration in a single V butt weld
d. Lack of sidewall fusion and incompletely filled groove

82
Q

ACFM cleaning standard

A

SA2

83
Q

ACDP cleaning standard

A

SA 2.5

84
Q

Eddy current cleaning standard

A

SA 2

85
Q

Radiography cleaning standard

A

SA 1

86
Q

FMD cleaning standard

A

SA 2

Note: No cleaning reuired when Assessing the integrity of tubular members with Caesium 137 only used by ROV

87
Q

…….is an example of in service defect?

A

Poor repair

88
Q

……….is an example of a construction defect

A

Tearing

89
Q

……….is an example of a construction defect

A

Honeycombing

90
Q

……….is an example of a construction defect

A

Blowholes

91
Q

The following statement concerning weld defects is true

A

Poor stop start is an imperfect shape defect

92
Q

The cathodic reaction is also known as?

A

Reduction

Remember:
ANOX REDCAT
Anode =Oxidation
Reduction = Cathode

OILRIG
Oxidation is Loss of Electrons, Reduction is gain of electrons

93
Q

Changing f-stop from f8 to f11 will produce what effect

A

Half the amount of light entering the camera

Increasing the f-stop from f/8 to f/11 will decrease the size of the lens aperture, resulting in a smaller opening. This change will increase the depth of field in your photograph, making more of the scene in focus. However, it also reduces the amount of light entering the camera, so you may need to adjust other settings, like ISO or shutter speed, to maintain proper exposure.

94
Q

Which focal length will give a wider field of view

A

A shorter focal length will provide a wider field of view. So, for example, a 24mm lens will generally have a wider field of view compared to a 50mm lens.

95
Q

Which of the following is the correct description of delamination?

A

A Category in service defect

96
Q

…….is an in-service planar defect

A

A fatigue crack

97
Q

What is a planar defect?

A

These have a large surface area but small volume such as cracks and
laminations. They are essentially 2 dimensional.

98
Q

What is a volumetric defect

A

Inclusions, porosity and other internal flaws that have a large volume
compared to surface area are in this category. They are 3 dimensional and
will also include undercut and lack of penetration. This category of defect is
caused during fabrication, not in-service; while planar defects may be
caused by in-service deterioration.

99
Q

A Bathycorromter reading of -845mV would indicate?

A

The structure is cathodically protected

100
Q

ACFM combines which of the following pairs of techniques to determine the length and depth of a surface breaking defect?

A

Eddy current and ACPD

101
Q

Vibrations in a platform leg, which are at 90 degrees to the tidal current flow is caused by

A

Vortex shedding

102
Q

A vertical steel pipe that carries crude away from a production platform is called a?

A

Export riser

103
Q

A reddish brown stain is seen during a visual inspection of a concrete structure it should be ?

A

Reported

104
Q

A binding agent in concrete is which of the following

A

Cement

105
Q

A fatigue crack will most likely be found in ?

A

The weld toe

106
Q

In a concrete structure,what prevents the steel reinforcement from corroding?

A

The high pH

107
Q

The electrical current produced in an electrolyte between two metals would be strongest between?

A

Silver and Aluminium

Galvanic Series in seawater.
Noble Top
Graphite
Gold Platinum
Silver
Stainless steel
Monel
Copper
Niobium
Tungsten
Lead
Cast iron
Mild steel
Aluminium
Zinc
Magnesium
Less Nobble bottom

Anything less noble than steel will corrode to protect the steel

108
Q

The following metal in contact with steel in an electrolyte could cause the steel to corrode?

A

Copper

Galvanic Series in seawater.
Graphite
Gold
Platinum
Silver
Stainless steel
Monel
Copper
Niobium
Tungsten
Lead
Cast iron
Mild steel
Aluminium
Zinc
Magnesium

109
Q

CP reading in contact with unprotected steel in seawater?

A

-450mmV to -640mV

110
Q

Assuming the surface is cleaned down to bare metal, which of the following cannot be found by visual inspection of the weld

A

Lack of sidewall fusion

111
Q

Name a property of the magnetic lines of flux?

A

They follow the path of least resistance

112
Q

A magnetic field is strongest where?

A

The lines of flux are packed closely together

113
Q

A material is said to be saturated when?

A

An increase in H (force) produces no increasing B (flux density)

114
Q

Which of the following could give rise to a leakage field during MPI?

A
  1. A sharp change in the magnetic permeability
  2. A sharp change in the components geometry
    e
  3. A crack running at 90deg to the magnetic flux lines

All of the above

115
Q

The following statement about the use of a permanent magnet for MPI is true

A

They have a high Coercivity

Low Permeability (Hard Ferromagnetic)
(Difficult to Magnetise)
High Retentivity
High Remanence
High Reluctance
High Coercivity

High Permeability (Soft Ferromagnetic) (Easily Magnetised)
Low Retentivity
Low Remanence
Low Reluctance
Low Coercivity

116
Q

Magnetic poles are ?

A

Points on a magnet where the flux lines enter or leave

117
Q

A field indicator is an instrument which can be used to?

A

Check for residual magentism

118
Q

The strength of an AC electromagnetic yoke is assessed by:

A

Measuring it’s lifting power.

The requirement is that the electromagnet must be able to lift 4 ½ kilograms
with pole spacing up to 300 mm

BS EN ISO 9934-1

119
Q

In its simplest form an atom is a positive a positive nucleus surrounded by electrons. What charge re these electrons?

A

Negative

https://youtu.be/2LEkjDiGcWw?si=Y63oTGI3-5BMb28L

120
Q

When an electron is either added or taken from the group surrounding an atom, the overall charge is no longer zero. The condition of the atom at this stage is called:

A

Ionic

https://youtu.be/2LEkjDiGcWw?si=Y63oTGI3-5BMb28L

121
Q

If the atom loses an electron it it becomes a positive ion an has a positive charge. This may be referred to as a

A

Cation

https://youtu.be/EIAaGHK5pjA?si=iyqqGNvKjsx7zgW3

122
Q

The following reaction occurs at the cathodic site?

A

Reduction

The Cathodic Reaction
These ‘free’ electrons formed in the anode reaction must be ‘used up’ if the
reaction is to proceed. This part of the reaction in the electrochemical corrosion
process therefore takes place at the site where the free electrons are
neutralised and is known as the cathodic reaction. Alternatively reactions such
as this that consume electrons are also known as reduction reactions

Remember:
ANOX REDCAT
Anode =Oxidation
Reduction = Cathode

OILRIG
Oxidation is Loss of Electrons, Reduction is gain of electrons

123
Q

The anode usually corrodes because of a

A

Loss of electrons

124
Q

Pitting is which type of corrosion?

A

Localised

125
Q

A form of corrosion that forms along the toe of the weld due to higher energy regions is often called

A

Weld decay

Weld decay, or preferential corrosion, is an example of this type of decay. In this case the boundary is the fusion boundary that forms along the toe of the weld and is a region of higher energy. This region becomes the anode and corrosion sets in, often giving quite significant visual indications of its presence.

126
Q

Fretting corrosion occurs at areas

A

Materials under
load subjected to vibration and slip.

127
Q

What environmental factors affect the corrosion rate ?

A

Temperature
Water flow rate
The pH of the electrolyte

128
Q

A working riser which become hot during service ?

A

Is particularly susceptible to corrosion and must be inspected more frequently

129
Q

Steel corrodes least when it is submerged in an electrolyte that has a pH value between

A

11-12
A high pH level is described as alkaline or basic.

130
Q

Describe a caisson

A

An open bottomed tubular component terminating at various depths for the purpose of the intake or discharge of water or waste

131
Q

Tension leg platforms are held in position by?

A

Piled steel anchor bases and vertical tendons

132
Q

FPSO stands for

A

Floating production and storage operations

133
Q

FPSO’s can offer advantages over platforms because:

A

They can reach remote parts of the field inaccessible to the existing platform
They can develop a field too small to warrant the cost of a fixed platform
They can develop a wider spread field using dedicated floating production systems (FPS) and linking the wells with pipelines.
Note: All of the above

134
Q

Traditional pipelines are made up of sections of what given length?

A

12.1m

135
Q

A typical field joint is joined by what type of weld

A

Full penetration but weld

136
Q

A typical field joint is covered in what?

A

Bitumen and protective wrap

137
Q

What is an alternative name for an anchorage point when referring to concrete

A

Cachetage point

138
Q

Describe a conductor

A

Tubes for drilling purposes connecting seabed wells to the topside

139
Q

What is the purpose of a breakwater wall?

A

To dissipate wave energy in the splash zone

140
Q

Define Permeability

A

Permeability has been defined as the ease with which a material can be magnetised. Of course, it is only some of the ferromagnetic group that are usefully magnetised. Those that are easy to magnetise are: -
™ Soft iron
™ Low carbon steel

141
Q

Define coercive

A

Coercive Force
The amount of reverse magnetic field which must be applied to a magnetic
material to make the magnetic flux return to zero. (The value of H at point Hc on the
hysteresis curve).

142
Q

Define reluctance

A

Reluctance
It is a term
used to describe the opposition that a ferromagnetic material shows to the
establishment of a magnetic field. Reluctance is comparable to the resistance in
an electrical circuit, however it does not have units while resistance does of
course. (This term is sometimes used as the opposite of permeability; low permeability would
indicate high reluctance and visa versa).

143
Q

Define retentivity

A

Retentivity: it is a material’s ability to retain a certain
amount of residual magnetic field when the magnetizing force is removed after
achieving saturation. (The value of B at point Br on the hysteresis curve, Figure 9.11).

144
Q

Magnetic poles are

A

Points on a magnet where the flux lines enter or leave

145
Q

A field indicator instrument which can be used to:

A

Check for residual magnetism

146
Q

The strength of an electromagnetic yoke is assessed by

A

Measuring it’s lifting power

Strength Required for MPI Electromagnets
BS EN ISO 9934-
1:2001.

4 ½ kilograms - pole spacing up to 300 mm.

147
Q

MPI indications which appear indistinct and fuzzy as apposed to strong and well defined are often caused by?

A

Sub surface defects

148
Q

The concentration of ferrous oxide particles in MPI can be checked by

A

A settlement test

Ink BS EN ISO 9934-2
Settlement / Suntherland = 100ml / 60 min
Ferrous Oxide 0.1% - 0.3% by volume
Additives no more than 10% by weight

149
Q

The ferrous oxide particles concentration of fluorescent MPI ink is typically in what range?

A

Fluorescent Inks
Ferromagnetic particles 0.1% to 0.3% by volume

150
Q

The ferrous oxide particles concentration of non- fluorescent MPI ink is typically in what range?

A

Non-fluorescent Inks
Ferromagnetic particles 1.25% to 3.5% by volume in the ink

3.2u Refresher updated Jan 2024 (12 decks)

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