Term
Deadlegs in hot piping systems may have corrosion rates that are signnificantly higher due to :
- caustic vaporizing
- convection currents
- crevice corrosion
- sulfidation
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Definition
Deadlegs in hot piping systems may have corrosion rates that are signnificantly higher due to :
Convection Currents |
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Term
Corrosion can occur in deadlegs of tower overhead systems as a result of:
- dew-point corrosion
- HTHA
- napthenic acid
- temper-embrittlement
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Definition
Corrosion can occur in deadlegs of tower overhead systems as a result of:
dew-point corrosion |
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Term
Corrosion can occur in some deadlegs at hydrotreating units. This is caused by:
-
Ammonium salts
-
oxygen pitting
-
SSC
-
Sulfidation
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Definition
Corrosion can occur in some deadlegs at hydrotreating units. This is caused by:
Ammonium salts |
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Term
CUI can be a major issue on insulated carbon steel piping systems operating between:
- 25-250 deg F
- 10-350 degs F
- 40-125 degs F
- 120-400 degs F
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Definition
CUI can be a major issue on insulated carbon steel piping systems operating between:
10-350 degs F |
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Term
CUI can be a major issue on insulated Stainless-steel piping systems operating between:
- 25-250 deg F
- 10-350 degs F
- 40-125 degs F
- 120-400 degs F
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Definition
CUI can be a major issue on insulated Stainless-steel piping systems operating between:
120-400 degs F
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Term
CUI is a inspection concern for insulated piping operating at 500 deg. and:
- is in intermittent service
- is mad of stainless steel
- is made of low chromes
- have poorly maintained insulation
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Definition
CUI is a inspection concern for insulated piping operating at 500 deg. and:
is in intermittent service
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Term
CUI of austenitic stainless steel piping:
- occurs at temperatures between -10 to 125 deg F
- normally appears as stress corrosion cracking
- is the result of using insulation that contains a sulfur compound
- normally causes deep isolated pitting
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Definition
CUI of austenitic stainless steel piping:
normally appears as stress corrosion cracking |
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Term
CUI is particularly aggressive:
-
in dry climates
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when operating temperatures cause frequent condensation and re-evaporation of atmospheric moisture.
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when operation temperatures are above 325 deg F
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if the insulation is made of fiberglass
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Definition
CUI is particularly aggressive:
when operating temperatures cause frequent condensation and re-evaporation of atmospheric moisture.
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Term
IF the buied piping is uncoated at grade, the inspector should consider exacavation to check for soil-to-air corrosion. What is the recommended depth to excavate?
- 1 to 3 "
- 6"
- 6' to 12"
- 12" to 24"
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Definition
IF the buied piping is uncoated at grade, the inspector should consider exacavation to check for soil-to-air corrosion. What is the recommended depth to excavate?
6' to 12"
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Term
The inspector checks the concrete-to-air interface of buried piping that does not have cathodic protection. Deterioration is noted. It may be necessary to remove the concrete and inspect beneath the pipe surface if this piping system is over:
- 5 yr old
- 10yr old
- 15yr old
- 25 yr old
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Definition
The inspector checks the concrete-to-air interface of buried piping that does not have cathodic protection. Deterioration is noted. It may be necessary to remove the concrete and inspect beneath the pipe surface if this piping system is over:
10yr old |
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Term
Sufidation of carbon steels begins to occur when the sulfur content is greater
than 0.5% and the temperature exceeds:
-
250 deg F
-
450 deg F
-
800 deg F
-
900 deg F
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Definition
Sufidation of carbon steels begins to occur when the sulfur content is greater
than 0.5% and the temperature exceeds:
450 deg F |
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Term
Some of the crude unit piping operates at a temperature where sulfidation can occur. Which material is most susceptible to attack?
- A-53
- A-106
- 300 series SS
- 400 series SS
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Definition
Some of the crude unit piping operates at a temperature where sulfidation can occur. Which material is most susceptible to attack?
A-53 |
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Term
A caustic piping system has external heat tracing. On this system, poorly designed heat tracing can cause:
- erosion/corrosion
- thermal fatique
- stress corrosion cracking
- polythionic cracking
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Definition
A caustic piping system has external heat tracing. On this system, poorly designed heat tracing can cause:
stress corrosion cracking |
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Term
Which of the following areas is least likely to be affected by corrosion/erosion?
- upstream of a pump
- downstream of a control valve
- flow direction changes
- Near orifice plates
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Definition
Which of the following areas is least likely to be affected by corrosion/erosion?
upstream of a pump |
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Term
When erosion damage occurs, which of the following corrosion patterns is least likely to occur?
- Grooving
- Waves and vallys
- Rouned holes
- Uniform wall loss
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Definition
When erosion damage occurs, which of the following corrosion patterns is least likely to occur?
Uniform wall loss |
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Term
Polythionic acid SCC occurs on what type of material?
- Annealed Ferritic staninless steel
- Sensitized austenitic stainless steel
- Normalized low chromes
- Non-stress relieved carbon steel
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Definition
Polythionic acid SCC occurs on what type of material?
Sensitized austenitic stainless steel |
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Term
Chloride stress corrosion cracking occurs on what type of material?
-
Austenitic SS
-
Ferritic SS
-
Carbon Steel
-
Low chromes
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Definition
Chloride stress corrosion cracking occurs on what type of material?
Austenitic Stainless Steel
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Term
Amine SCC occurs on what type of material?
- Annealed ferritic SS
- Sensitized austenitic SS
- Normalized low chromes
- Non-stress relieved carbon steel
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Definition
Amine SCC occurs on what type of material?
Non-stress relieved carbon steel |
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Term
During a turnaround, environmental cracking is detected during an interal inspection of a pressure vessel. The inspector should:
-
inspect the downstreem piping for environmental cracking
-
inspect the upstream piping for environmental cracking
-
inspect both the upstream and downstream piping for environmental cracking
-
inspect ustream and downstream piping approximately 12" or 3 diameters (whichever is greater) away from the vessel nozzle.
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Definition
During a turnaround, environmental cracking is detected during an interal inspection of a pressure vessel. The inspector should:
Inspect both the upstream and downstream piping for environmental cracking |
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Term
An internal inspection is being conducted on a refractory-lined piping system. how much refractory should be removed to check the condition of the pipe's internal surface?
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A min of 10% should be removed
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A small area of refractory should be removed on each length of pipe
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At least one small area of refractory should be removed in the most suspect area
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Removal of refractory is not required unless there is reason to suspect that corrosionis occurring under the refractory
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Definition
An internal inspection is being conducted on a refractory-lined piping system. How much refractory should be removed to check the condition of the pipe's internal surface?
Removal of refractory is not required unless there is reason to suspect that corrosionis occurring under the refractory |
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Term
Which of the following is not a cause of fatigue cracking?
-
Piping vibration
-
Pressure cycles
-
Thermal cycles
-
Viscosity cycles
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Definition
Which of the following is not a cause of fatigue cracking?
Viscosity cycles |
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Term
Fatigue cracking can typically be first detected at:
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piping supports and hangers
-
misaligned flaged connections
-
branched connections
-
socket-weld fitting
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Definition
Fatigue cracking can typically be first detected at:
Branched connections |
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Term
Each of the following piping system operates with daily temperature cycle of over 400 deg F. In which system is fatigue cracking most likely to occur?
-
Pipe welds having dissimilar materials, e.g. carbon steel & stainless
-
Butt welded low chrome piping
-
Butt welded sensitized austenitic stainless steel
-
No-stress relieved carbon steels
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Definition
Each of the following piping system operates with daily temperature cycle of over 400 deg F. In which system is fatigue cracking most likely to occur?
Pipe welds having dissimilar materials, e.g. carbon steel & stainless |
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Term
Fatigue cracking is difficult to find using NDE because:
-
The cracking location are difficult to predict
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The cracking is very tight and not easy to find with conventional PT techniques
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Once the cracking initiates it may take only a few days before the crack progresses 100% through the pipe wall
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the NDE technicians are not available, they are in the tank farm sleeping in the back of the RT truck
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Definition
Fatigue cracking is difficult to find using NDE because:
Once the cracking initiates it may take only a few days before the crack progresses 100% through the pipe wall |
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Term
Creep cracking is depenent on:
-
Cycles, time and temperature
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cycles, temperature and stress
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time, temperature, and pressure
-
time, temperature, and stress
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Definition
Creep cracking is depenent on:
time, temperature, and stress
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Term
Creep cracking begins to occur on 1 1/4 Cr steels operating above:
- 450 deg f
- 700 deg F
- 900 deg F
- 1100 deg F
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Definition
Creep cracking begins to occur on 1 1/4 Cr steels operating above:
900 deg F |
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Term
Most brittle fractures have occurred:
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during the 1st year of srvice
-
during the first hydrostatic test
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after the material has been overheated and then cooled
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when using relatively thin walled piping
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Definition
Most brittle fractures have occurred:
during the first hydrostatic test |
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Term
Low alloy steels (specially 2 1/4 Cr-1 Mo materials) are subject to:
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Temper embrittlement
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Brittle fracture
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Environmental cracking
-
Fatigue cracking
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Definition
Low alloy steels (specially 2 1/4 Cr-1 Mo materials) are subject to:
Temper embrittlement |
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Term
Low chromes steels:
-
may be brittle when operation above 650 deg F
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may be brittle at ambient temperatures after operating above 650 deg F
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are subject to polythionic cracking when operating above 650 deg F
-
are subject to SCC when operating above 650 deg F
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Definition
Low chromes steels:
may be brittle at ambient temperatures after operating above 650 deg F |
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Term
Temper embrittlement occurs in certain materials when:
-
the operation temperature is within 30 deg F of the piping's MDMT
-
weld repairs are performed and the metal temperature is below 32 deg f
-
the process temperatures exceed 650 deg F
-
the proces environment contains low temperature caustic
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Definition
Temper embrittlement occurs in certain materials when:
the process temperatures exceed 650 deg F |
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Term
Low chrome materials are subject to temper-embrittlement. these materials are:
- Brittle when new
- become brittle due to welding
- brittle at temperatures above 650 deg F
- brittle at low temperatures due to metallurgical changes that occurred during high temperature operation
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Definition
Low chrome materials are subject to temper-embrittlement. these materials are:
brittle at low temperatures due to metallurgical changes that occurred during high temperature operation |
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