API572

Question 1

Magnetic flux scanning techniques are also available that provide a fast qualitative technique for the detection of corrosion losses on large surface areas for vessels up to

Answer 1

0.5 in. (1.3 cm) wall thickness.

Question 2

Radiographs are taken with a ______of known thickness that will show on the developed film of the vessel part in question.

Answer 2

step gauge

Question 3

API 510 recognizes that corrosion rate, corrosion allowances, rerating, and component assessment by __________ methodology may all be used to establish retirement and next inspection criteria

Answer 3

ASME BPVC Section VIII, Division 2,

Question 4

API 510 contains additional guidance

Answer 4

on the rating of pressure vessels.

Question 5

The consequence of possible failure of such parts should be considered when setting these limits. What limtis

Answer 5

minimum thickness values

Question 6

Safety is the prime factor affecting

Answer 6

retiring thickness

Question 7

Excessive heat, mechanical shock, corrosion of reinforcing steel, or the freezing of entrapped moisture can cause

Answer 7

cracking in and around supports.

Question 8

Cracks in concrete or fireproofing may be caused by (5)

Answer 8

excessive heat, poor design or material, mechanical shock, or unequal settlement.

Question 9

Taking diameter measurements at several points approximately ________ apart can check distortion of cylindrical skirts

Answer 9

60° (1.0 radian)

Question 10

The inside surface of a skirt sheet is often subject to attack by

Answer 10

by condensed moisture,

Question 11

Fireproof inspection method (2)

Answer 11

1. Visual examination aided by scraping will disclose most defects
2. Very light taps with a hammer will disclose lack of bond between concrete fireproofing and the protected steel.

Question 12

Catalytic reformer equipment operating at temperature more than _____may experience creep embrittlement damage during operation.

Answer 12

900 °F(482 °C)

Question 13

Recommended resistance is ____ohms or less, and resistanceis not to exceed 25 ohms.

Answer 13

5 ohms

Question 14

Inspection for CUI should be considered for externally insulated vessels subject to moisture ingress and that operate between __________) for carbon and low-alloy steels, and _____________ for austenitic stainless steels, or are in intermittent service. This inspection may require removal of some insulation. However, visual inspection at ports used for thickness measurement loc

Answer 14

10 °F (-12 °C) and 350 °F (175 °C

140 °F (60 °C) and 400 °F (205 °C)

Question 15

Under normal conditions, at least ____measurement in each shell ring and one measurement on each head should be taken.

Answer 15

one

Question 16

Inspect vessels in cyclic service at external supports using either_____(2) for fatigue cracking.

Answer 16

PT or MT

Question 17

Certain types of corrosion may be found on external surfaces of a vessel. Among these are (4)

Answer 17

atmospheric corrosion, caustic embrittlement, hydrogen blistering, and soil corrosion.

Question 18

ATM corrosion

Answer 18

In humid areas and in areas where corrosive chemical vapors are present in the air, corrosion of external shell surfaces may be a problem. Vessels operating in a temperature range that will permit moisture to condense are most susceptible. Corrosion of this type is usually found by visual inspection

Question 19

caustic embrittlement

Answer 19

This type of attack is most likely to occur at connections for internal heating units and in areas of residual or other high stress. The more susceptible areas are around nozzles and in or next to welded seams. Frequently, visual inspection will disclose this type of attack. The caustic material seeping through the cracks will often deposit white salts that are readily visible.

MT (wet or dry), PT, and angle beam UT may also be used to check for caustic embrittlement.

Question 20

hydrogen blistering

Answer 20

areas below the liquid level in vessels that contain acidic corrosion products are more likely to be subject to hydrogen blistering. Hydrogen blistering is typically found on the inside of a vessel. However, hydrogen blisters may be found on either the ID or OD surface, depending on the location of the void that causes the blistering. Blisters arefound most easily by visual examination. A flashlight beam directed parallel to the metal surface will sometimes reveal blisters. When many small blisters occur, they can often be found by running the fingers over the metal surface.

Question 21

soil corrosion.

Answer 21

The most severe corrosion will usually be found between ground level and up to several inches below. Visual examination, supplemented by picking and tapping, will disclose most faults. This corrosion will be particularly intense in areas where cinder fills were used or where acid splash-over has occurred.

Question 22

Unless readily visible, leaks are best found by (2)

Answer 22

pressure or vacuum testing the vessel.

Question 23

If visual inspection is not sufficient (often the case in the detection of amine and deaerator cracking), ____(7) analysis may be used to locate and provide additional information on the structural significance of cracks or other discontinuities

Answer 23

wet or dry MT, angle beam UT, PT, or acoustic emission .

Question 24

The wet fluorescent magnetic particle technique (WFMPT) analysis is ____sensitive than dry MT techniques

Answer 24

more

Question 25

A check of the skin temperature of the metal in the hot spot area can be made by using a (4)

Answer 25

portable thermocouple, infrared equipment, or temperature-indicating crayons or special paints.

Question 26

Using replication techniques or taking a material sample (a boat or other sample) should be considered if carbon steel temperatures were in the range of________

Answer 26

750 °F to 1000 °F

Question 27

depending on operating conditions and alloy , or if temperatures in the creep range are suspected, an experienced

Answer 27

metallurgist or engineer should be consulted.

Question 28

Austenitic stainless steels are particularly susceptible to (2)

Answer 28

polythionic acid stress corrosion cracking (PASCC) and chloride corrosion

Question 29

Areas of the vessel opposite inlet nozzles maybe subject to (2)

Answer 29

impingement attack or erosion.

Question 30

Vessels in water service, such as exchangers or coolers, are subjected to maximum corrosion where the water temperatures are

Answer 30

highest.

Question 31

corrosion may occur where dissimilar metals are in

Answer 31

close contact.

Question 32

Cracks in vessels are most likely to occur where there are sharp changes in shape or size or near welded seams, especially if ______is applied.

Answer 32

high stress

Question 33

When materials flow at high velocities in exchanger units, an ________can be expected if changes are made in the direction of flow.

Answer 33

accelerated attack

Question 34

Shells of vessels _____to inlet impingement plates are susceptible to erosion

Answer 34

adjacent

Question 35

If large areas are deeply corroded, _____may be necessary.

Answer 35

abrasive blasting

Question 36

_______ of the vessel should be inspected for corrosion, erosion, hydrogen blistering, deformation, cracking, and laminations.

Answer 36

All areas

Question 37

Pitting corrosion can usually be found by scratching suspected areas with a __________

Answer 37

pointed scraper.

Question 38

When cracks are suspected or found, their extent can be checked with (2)__NDE_______.

Answer 38

PT or MT (wet or dry) techniques.

Question 39

_______inspection methods provide a volumetric inspection of potential flaw areas.

Answer 39

Angle beam UT

Question 40

The most sensitive method of locating surface cracking is the ______method. Other valuable methods are the dry MT, PT, UT, or radiographic methods.

Answer 40

WFMPT

Question 41

Examination for cracking should include pressure boundary welds and heat-affected zones up to ___ from the welds.

Answer 41

4"

Question 42

____ is the primary recommended internal examination method for Deaerators . Other techniques include ACFM and surface eddy current.

Answer 42

WFMPT

Question 43

Erosion is characterized by a ________ marked absence of the erosion product, and metal loss,

Answer 43

smooth, bright appearance,

Question 44

Areas directly above and below the liquid level in vessels with a process containing acidic components may be subject to

Answer 44

hydrogen blistering

Question 45

High-temperature hydrogen attack (HTHA) is a damage mechanism that reduces the______ and___(2) of steel by a high temperature reaction of absorbed hydrogen with carbon in the steel resulting in decarburization and internal fissuring.

Answer 45

strength and ductility

Question 46

Shell and tray surfaces in contact with tray packing should be examined for possible _________

Answer 46

loss of metal by corrosion.

Question 47

MT inspection cannot be used on ____materials.

Answer 47

austenitic

Question 48

metallic liner inspection (2)

Answer 48

1. UT thickness instrument. | 2. remove a small section and check it with calipers

Question 49

Bulges and buckling often occur in metallic linings and usually indicate that _____or ____exist in the bulged section of the lining or that ____ exist in the adjacent welds.

Answer 49

cracks or leaks / pin holes

Question 50

The bulges are formed either by the expansion or buildup of a material that seeps behind the lining during operation or by __________

Answer 50

differential thermal expansion.

Question 51

An AUT can provide the most reliable NDE of flaws detected in the lining or base material. Although these techniques can be applied at ambient or elevated vessel temperatures, flawsizing is most accurate at or near __________

Answer 51

ambient temperatures.

Question 52

Removal of representative lining sections to permit visual examination of the vessel wall is always

Answer 52

preferred if feasible.

Question 53

(3) are all indications that openings exist in the non metallic lining.

Answer 53

Bulging, blistering, and chipping

Question 54

Considerable care should be exercised when working inside vessels lined with (4)________. These coatings are highly susceptible to mechanical damage.

Answer 54

glass, rubber, plastic sheets, or paint

Question 55

. Bulging can be located visually and is usually accompanied by __________

Answer 55

cracking.

Question 56

The sound and feel of ______ on loose concrete lining usually make such looseness evident.

Answer 56

light hammer tapping

Question 57

_____examination will reveal most mechanical damage (dents, gouges, and cracks).

Answer 57

Visual

Question 58

ET, alternating current field measurement, and UT methods are available for the detection of ________

Answer 58

surface breaking flaws.

Question 59

(2) are used to analyze flaws, usually in welded seams, that are not visible on the surface of the metal.

Answer 59

Radiography and angle beam UT

Question 60

(3)_______ are three methods of detecting metallurgical changes.

Answer 60

Hardness, chemical spot, and magnetic tests

Question 61

_____ can be used to detect faulty heat-treating, carburization, nitriding, decarburization, and other processes that cause changes in hardness.

Answer 61

Portable hardness testers

Question 62

It is not recommended to hammer test objects under

Answer 62

pressure.

Question 63

_______analysis has been developed for use in conjunction with pressure testing or during equipment cooldown

Answer 63

acoustic emission

Question 64

(2) methods should be used on major repairs, and if required by the applicable construction code, (2) should also be performed.

Answer 64

MT and PT / radiographic, or angle beam UT examination

Question 65

The two most common types of trays are _____

Answer 65

cascade trays are shed trays and disk/donut trays.

Question 66

sieve trays can be subdivided into (2)

Answer 66

single-flow and dual-flow trays.

Question 67

Dual-flow trays are customarily used for processes that exhibit______

Answer 67

heavy fouling due to the formation of precipitates or polymers.

Question 68

Valve trays can be subdivided into (2)

Answer 68

fixed valve and floating valve trays. .

Question 69

Bubble caps remain in service throughout the industry in systems where ____liquid flow rates and ____variations in vapor flow and resistance to heavy fouling are required.

Answer 69

low / high

Question 70

packing has the advantage of being able to handle ____liquid rates with _____efficiencies and with lower-pressure drop than all but the newest of the high-capacity trays

Answer 70

larger / higher

Question 71

Most structured packing isinstalled such that each succeeding layer is ____ out from the previous layer

Answer 71

90°

Question 72

structured packing provides ____capacity and ____pressure drop than crosscurrent trays or random packing.

Answer 72

higher / lower

Question 73

Skirt Fireproofing—Any crack over ____in. in width, and any crack that has displacement or bulging of theconcrete fireproofing material should be investigated for corrosion under fireproofing (CUF).

Answer 73

0.250

Question 74

Preliminary, or “dirty inspections” should be performed upon opening th eexternal manways, before

Answer 74

whatever forced ventilation is to be installed is installed.

Question 75

what metal is more prone to denzintification

Answer 75

brass

Question 76

Portable hardness testers can be used to detect faulty (4)

Answer 76

heat-treating, carburization, nitriding, decarburization, and other processes that cause changes in hardness.

Question 77

Hardness, chemical spot, and magnetic tests are three methods of detecting

Answer 77

metallurgical vchanges.

Question 78

The use of NDE devices for inspection is subject to safety requirements customarily in_______ The use of hydrocarbon-based magnetic particle (MT) and/or liquid penetrant (PT) can change the environment of a confined inspection space.

Answer 78

gaseous atmospheres.

Question 79

Cracks in concrete or fireproofing may be caused by (4)

Answer 79

excessive heat, poor design or material, mechanical shock, or unequal settlement.

Question 80

hair-like appearance. on concrete, Such cracks are _______serious unless they expose the steel to corrosion.

Answer 80

not usually

Question 81

Distortion of anchor bolts may indicate serious

Answer 81

foundation settlement.

Question 82

_____may also be used to test bolts

Answer 82

UT

Question 83

_______ is one of the best methods of protecting steel structures from corrosion.

Answer 83

Galvanizing

Question 84

GUy wire inspection? (2)

Answer 84

Visual examination / AUT inspection is typically necessary to scan the entire length of guy wires for condition and proper loading.

Question 85

Guy wires clips should be spaced at least _____ apart to insure maximum holding power.

Answer 85

six rope diameters

Question 86

If there is any evidence of distortion or cracks in the area around the nozzles,_______

Answer 86

all seams and the shell in this area should be examined for cracks.

Question 87

(3)are the types of paint failures usually found.

Answer 87

Rust spots, blisters, and film lifting

Question 88

_________(Paint failure type) is not easily seen unless the film has bulged appreciably or has broken.

Answer 88

Film lifting

Question 89

The most likely spots to search for paint failure are in _____, in constantly moist areas, and at welded or riveted vessel seams.

Answer 89

crevices

Question 90

(2) methods can provide an on-stream assessment of areas with high moisture and can provide a screening assessment for CUI.

Answer 90

Neutron backscatter / Thermography

Question 91

Under normal conditions, at least one measurement in each (2) should be taken.

Answer 91

shell ring and one measurement on each head

Question 92

areas below the liquid level in vessels that contain acidic corrosion products are more likely to be subject to

Answer 92

hydrogen blistering.

Question 93

(3) ________ require thorough cleaning over wide areas.

Answer 93

Extensive cracking, deep pitting, and extensive weld damage

Question 94

The bottom head and shell of fractionators processing high-sulfur crude oils are susceptible to _______

Answer 94

sulfide corrosion.

Question 95

Cracks occurs (4)

Answer 95

a) attachment weld(s) of an internal component, b) main weld seams, c) gasket grooves (ring joint-flanges), d) nozzle attachment welds

Question 96

When damage is slight, ______may be sufficient on small vessels, but more measurements should be taken on large vessels.

Answer 96

one thickness measurement on each head and each shell course

Question 97

When damage appears to be widespread, ______assure an accurate determination of the remaining thickness.

Answer 97

enough readings should be taken to

Question 98

Shells of vessels _____to inlet impingement plates are susceptible to erosion.

Answer 98

adjacent

Question 99

Vessels in water service, such as exchangers or coolers, are subjected to maximum corrosion where the water temperatures are

Answer 99

highest.

Question 100

REboiler - The point where the _____ stream returns to the tower may be noticeably corrode

Answer 100

hot process

Question 101

wet hydrogen sulfide (H2S) or cyanide environments are susceptible to cracks in their (2) _______

Answer 101

welds and weld heat-affected zones.

Question 102

vessels where sludge may settle out, _____corrosion sometimes occurs.

Answer 102

concentration cell

Question 103

welds in vessels constructed (2) ______should be checked for cracks

Answer 103

of high-strength steels [(above 70,000 lbf/in.2 tensile (483 MPa)] OR coarse-grain steels

Question 104

tower trays primary NDE?

Answer 104

visual (UT if needed)

Question 105

Erosion or corrosion at the baffles of exchangers will often show up as a series of regularly spaced rings when a _________to the shell surface.

Answer 105

flashlight beam is place parallel

Question 106

Areas directly above and below the liquid level in vessels with a process containing acidic components may be subject to

Answer 106

hydrogen blistering

Question 107

Out-of-roundness can be caused by _________

Answer 107

welding

Question 108

Deaerators in boiler feedwater systems can be susceptible to _____from a corrosion fatigue mechanism

Answer 108

cracking

Question 109

hydrocrackers and hydrotreaters, use complete weld overlay that uses stabilized ________

Answer 109

austenitic stainless steel

Question 110

Bulging can be located visually and is usually accompanied by ________

Answer 110

cracking.

Question 111

breaks in coating are sometimes called

Answer 111

holidays.

Question 112

the _____method of inspection for leaks in paint, glass, plastic, and rubber linings

Answer 112

spark tester

Question 113

excess thickness of the shell or head plates is used

Answer 113

by the designer as nozzle reinforcement

Question 114

lined vessels are sometimes subject to severe corrosion due to

Answer 114

condensation on the shell behind the insulation

Question 115

pressure tested for (3)

Answer 115

integrity and tightness and redistribution at defects

Question 116

pneumatically, a (2)______ should be used to aid visual inspection.

Answer 116

UT leak detector or soap solution or both

Question 117

min test temp for <2" and >2"

Answer 117

1. 10F ABOVE MDMT | 2. 30F ABOVE MDMT

Question 118

min test temp for <2" and >2"

Answer 118

1. 10F ABOVE MDMT | 2. 30F ABOVE MDMT

Question 119

when testing a floating-head exchanger with the pressure in the TUBES, removal of the shell cover will reveal the source if the leak is in (3)

Answer 119

the gasket, stay bolts, or tube rolls at the floating head.

Question 120

when testing a floating-head exchanger with the pressure in the SHELL, removal with the channel cover off will reveal leaking

Answer 120

1. tube rolls at the stationary tubesheet, but will not clearly identify the source of leakage at floating tubesheet rolls or floating head gasket leaks.