API 574 6-10

Question 1

An inspection plan is often developed through the collaborative work of the

Answer 1

inspector, piping engineer, corrosion specialist, and operating personnel

Question 2

For piping systems, inspection plans should address the following:

Answer 2

a) condition monitoring locations (CMLs) for specific damage mechanisms;
b) piping contact points at pipe support;
c) pipe supports and support appurtenances;
d) corrosion under insulation (CUI);
e) injection points;
f) process mixing points;
g) soil-to-air (concrete-to-air) interfaces (SAIs);
h) dead-leg sections of pipe;
i) PMI;
j) auxiliary piping;
k) critical utility piping as defined by owner/user;
l) vents/drains;
m) threaded pipe joints;
n) internal linings;
o) critical valves;
p) expansion joints

Question 3

After an RBI assessment is conducted, the results may be used to establish the inspection plan and better define the following: (5)

Answer 3

a) the most appropriate inspection and NDE methods, tools, and techniques;
b) the extent of NDE (e.g. percentage of piping to examine);
c) the date for internal, external, and on-stream inspections;
d) the need for pressure testing after damage has occurred or after repairs/alterations have been completed;
e) the prevention and mitigation steps to reduce the probability and consequence of a piping failure (e.g. repairs, process changes, inhibitors, etc.).

Question 4

single most frequent damage mechanism leading to pipe replacement is

Answer 4

corrosion.

Question 5

factors to consider when establishing the corrosion-monitoring plan for process piping are: (5)

Answer 5

a) classifying the piping service in accordance with API 570 or risk ranking based on RBI analysis;
b) categorizing the piping systems into piping circuits of similar corrosion behavior
c) identifying susceptible locations where accelerated damage is expected
d) accessibility of the CMLs for monitoring when localized corrosion is not predicted;
e) RBI to identify high-risk piping circuits and/or specific piping locations

Question 6

pros of establish circuits ?

Answer 6

By identifying like environments and damage mechanisms as circuits, the spread of calculated corrosion rates of the CMLs in each circuit is reduced.

Question 7

mixing points concerns? (2)

Answer 7

corrosion or mechanical mechanisms (e.g. thermal fatigue)

Question 8

Other intensive inspection chosen for the damage mechanism is usually required mixing points? (4)

Answer 8

1. close grid thickness surveys,
2. UT scanning techniques, and
3. profile radiographic examination (RT) for corrosion. 4. Other NDE techniques (e.g. angle beam UT, PT, etc.) may be appropriate when inspecting for thermal fatigue cracking

Question 9

If the temperature difference between two process streams exceeds a certain (delta T),

Answer 9

a thermal sleeve may be needed in order to prevent thermal fatigue.

Question 10

why the quantity of water needs to be calculated carefully?

Answer 10

to ensure sufficient un-vaporized water remains to fulfill the function and not exacerbate corrosion.

Question 11

why are dead legs a concern? (3 )

Answer 11

dew-point or ammonium-salt or water can collect in dead-legs

Question 12

CUI is particularly aggressive where operating temperatures and what materials?

Answer 12

operating between 10 °F (–12 °C) and 350 °F (175 °C) / carbon steel and low-alloy piping systems,

Question 13

IS carbon steel and low-alloy piping systems that normally operate in service above 350 °F (175 °C), but are in intermittent service susceptible to CUI?

Answer 13

YES

Question 14

CUI concern for - austenitic stainless steel piping systems operating

Answer 14

between 140 °F (60 °C) and 350 °F (205 °C

Question 15

What NDE can examine the refractory for volumetric flaws and for separation from the shell surface

Answer 15

Microwave examination technique (MW)

Question 16

Preferred NDE methods of detecting fatigue cracking include

Answer 16

PT, MT, and angle beam UT when inspecting from the OD for ID cracking, and AE

Suggested locations for UT on elbows would include the 3 and 9 o’clock positions.

Question 17

creep cracking has been experienced in the industry is in ____Material___ and above ____ temp

Answer 17

1 1/4 Cr steels above 900 °F (482 °C).

Question 18

NDE methods of detecting creep cracking (5)

Answer 18

include PT, MT, UT, RT, and ET, and alternating current field measurement (ACFM), in-situ metallography, and dimensional verification (i.e. strapping pipe diameter) are other common practices for detection. and AE

Question 19

What material is susceptible to brittle failure at or below ambient temperatures.

Answer 19

Carbon, low-alloy, and 400SS

Question 20

NDE techniques that may allow inspection of touch points without lifting of the pipe or removal of the support (3)

Answer 20

1. Long-range Ultrasonic Technique:
2. Electromagnetic Acoustic Transducer (EMAT) Ultrasound
3. Creeping Head Wave Method

Question 21

What is Long-range Ultrasonic Technique pros (1) and cons (2)

Answer 21

pros
1. detection of internal and external corrosion from a single point of access on the pipe to a distance of about 30 m
cons
1. distance and effectiveness may be reduced by factors such as fittings, flanges, heavy external coatings and concrete, and heavy products inside the pipe
2. cannot differentiate between internal and external corrosion or may not locate the most severe localized corrosion

Question 22

Electromagnetic Acoustic Transducer (EMAT) Ultrasound (3)

Answer 22

1 . can be used to inspect pipe support locations on live, on-stream process piping
2 . survey pipe diameters NPS (4 in. to 24 in. NPS)
3. Transducers housed in a scanner that moves along the pipe measure the mode and velocity changes of the Lamb waves and convert the output into readings of wall thickness

Question 23

Creeping Head Wave Method

Answer 23

1. able to detect corrosion of a pipe at a distance from the point of access
2. can also be utilized to survey for corrosion between pipe and saddle supports.

Question 24

When defects are found in the waterproof coating of insulation, either (2)

Answer 24

1. enough insulation should be removed o

2. the affected area should be radiographed to determine the extent and severity of the corrosion.

Question 25

Tightening flange bolts in a pressurized line is only recommended when special steps are taken to avoid three potential problems:

Answer 25

a) bolt interactions—when a bolt is tightened the adjacent bolts are loosened, b) a bolt can yield or fail due to overloading, c) tightening one side of a flange can cause deflections in the areas opposite and adjacent to it.

Question 26

injection points concerns

Answer 26

corrosion and erosion

Question 27

what type of issue with pipe containing anime?

Answer 27

Stress corrosion cracking

Question 28

Piping leaks where should be giving most attention?

Answer 28

flanged joints, packing glands, bonnets of valves, and expansion joints on piping

Question 29

Spring hanger loads should be checked under

Answer 29

both cold and hot conditions,

Question 30

Improper spring support settings can cause excessive

Answer 30

pipe loads on rotating equipment that can result in misalignment.

Question 31

how do you inspect non-destructively for loose or broken foundation bolts ?

Answer 31

Lightly rap the bolts sideways with a hammer while holding a finger against the opposite side.

Question 32

pipe line that is vibrating and swaying. What is one of the most important things you would you check for and where would you check?

Answer 32

Welds should be inspected for cracks, particularly at points of restraint.

Question 33

primary means (NDE) for thickness measurement? (2)

Answer 33

1. primary UT | 2. RT

Question 34

UT devices should have training on the proper use of this equipment, including

Answer 34

ultrasonic theory, high-temperature thickness measurements, corrosion evaluation, midwall anomalies, potential for “doubling,” and equipment operations.

Question 35

Numeric Thickness Readout (3)

Answer 35

1. dual-element pitch-catch transducers 2. probe zero and a velocity setting for calibration 3. range on for these instruments usually ranges from 0.040 in. to 20.000 in

Question 36

A-scan with Numeric Thickness Readout (3)

Answer 36

1. incorporate a numeric display and an electronic display for viewing an A-scan presentation 2. The advantage to an A-scan display over a numeric display is that it allows the examiner to view the ultrasonic waveform to verify the proper signal is being measured by the instrument. to avoid doubling and for evaluating a laminar indication vs. corrosion damage 43. these instruments primarily use a 0.250-in. to 0.500-in. diameter, 2.0 MHz to 5.0 MHz, dual-element pitch-catch search unit, but some instruments have options to use single-element delay or even EMATs.

Question 37

Doubling occurs when measuring

Answer 37

wall thickness below the instrument/transducers ability to separate the signals adequately for proper measurement gate function. This problem can occur on thin wall below approximately <0.1 in. thickness and for evaluating a laminar indication vs. corrosion damage.

Question 38

Ultrasonic Flaw Detectors with a Numeric Display

Answer 38

1. similar to a-scan | 2. a lot more options and features, including the capability for angle beam examinations

Question 39

Ultrasonic velocities are different in

Answer 39

different materials

Question 40

The best search units for conducting corrosion evaluation are

Answer 40

dual-element transducers

Question 41

UT high-temperature search units are designed to withstand temperatures up to

Answer 41

1000 °F (538 °C)

Question 42

As the test specimen temperature increases above ambient temperature, the velocity of the material _____ and increasing the as- measured ultrasonic thickness by a factor _% / F_

Answer 42

decreases, / 1 %/100 °F (1 %/55 °C)

Question 43

RT primary functions of this method are to detect (2)

Answer 43

metal loss and check weld quality

Question 44

Radiography has the following advantages:

Answer 44

a) pipe insulation can remain intact; b) the metal temperature of the line has little bearing on the quality of the radiograph c) radiographs of small pipe connections, such as nipples and couplings, can be examined for thread contact, corrosion, and weld quality; d) film provides a permanent visual record of the condition of the piping at the time of the radiograph; e) the position of internal parts of valves (dropped gates) can be observed; f) radiographic equipment is easily maneuverable in the refinery or chemical plant; g) isotope radiography is not an ignition source in the presence of hydrocarbons; h) pitting and other nonuniform corrosion can be identified; i) provides a view of a large area.

Question 45

RT thickness measurement accuracy relies on (2)

Answer 45

exposing the films and the person reviewing them

Question 46

The locations most susceptible to cracking are (2)

Answer 46

welds and the heat-affected zones

Question 47

Other areas prone to cracking are locations that contain crevices, such as

Answer 47

socket-welded piping, flange surfaces, or threaded joints.

Question 48

MT PT and UT can be used on what type of materials.

Answer 48

``` MT = magnetic PT/UT = both nonmagnetic and magnetic materials ```

Question 49

The depth of a crack may be determined by (2)

Answer 49

NDE or by chipping or grinding until sound metal is reached

Question 50

Whenever valves are removed from service for overhaul or refurbished for reuse, they should be inspected and tested to the requirements of API

Answer 50

598.

Question 51

Flange joints can be inspected while in service by applying (2)

Answer 51

single-element or phased array UTs to the external surfaces to measure flange face corrosion and to detect ring groove cracking.

Question 52

Cracks in alloy-steel welds are often associated with excessive hardness resulting from

Answer 52

improper control of preheat or PWHT.

Question 53

leaking threaded joint should not be tightened

Answer 53

while the system is in service under pressure

Question 54

misalignment is not apparent until the piping has

Answer 54

cooled and has moved to its cold position.

Question 55

metal temperatures of about 800 °F (427 °C) and above—should be measured to check

Answer 55

for creep or deformation with time under stress.

Question 56

Inspection of expansion joints involves examinations both at maintenance (2)

Answer 56

outages and during operation prior to shutdown and shortly after start-up

Question 57

FRP - Joints with up to 85 % disbond have reportedly passed

Answer 57

pressure tests.

Question 58

Many traditional NDE techniques and testing are used to assess nonmetallic piping. (6)

Answer 58

a) UT, b) RT, c) AE, d) hardness testing, e) thermographic imaging, f) MW.

Question 59

size of Tell-tale holes?

Answer 59

1/8"

Question 60

There are three well-known methods of determining resistivity.

Answer 60

These are the Wenner Four-pin Method, the soil bar (AC bridge), and the soil box.

Question 61

The Four-pin Method uses the formula:

Answer 61

resistivity (ohm-cm) = 191.5 x d xR

Question 62

the Four-pin Method may not be applicable.

Answer 62

in cases of parallel pipes or in areas of intersecting pipelines,

Question 63

The soil bar is typically inserted

Answer 63

to the depth in the soil where the resistivity is to be taken.

Question 64

During the execution of repairs, the inspector should ensure that the work is executed per the scope and meets code requirements. Typical inspector activities include: (4)

Answer 64

a) ensuring NDE is performed at the hold points as stated in the inspection plan; b) reviewing examination results to ensure that they meet code and specification requirements; c) ensuring any heat treatment is performed per the work scope; d) ensuring testing requirements, such as hardness and pressure testing, are performed and acceptable.

Question 65

Additional thickness is often needed near _______connections.

Answer 65

branch

Question 66

Metallic pipe for which t ≥ D/6 or P/SE > 0.385 requires

Answer 66

special consideration

Question 67

ASME B31.3 contains a formula for determining the required thickness of

Answer 67

new, uncorroded, straight pipe subject to internal pressure

Question 68

API 570 permits the use of the simple Barlow formula to determine the required wall thickness for

Answer 68

in-service piping

Question 69

Additional consideration and allowances for structural thickness may be required for the following conditions (6)

Answer 69

b) Piping diameters greater than 24 in. (610 mm). c) Temperatures exceeding 400 °F (205 °C) for carbon and low-alloy steel. d) Higher alloys (other than carbon steel and Cr-Mo). e) Spans in excess of 20 ft (6 m). f) High external loads (e.g. refractory lined, pipe that is also used to support other pipe, rigging loads, and personnel support loading). g) Excessive vibration.

Question 70

Austenitic stainless steel piping often have lower minimum structural thickness requirements based

Answer 70

upon their typically higher strength, higher toughness and thinner initial thicknesses of piping components.

Question 71

Valves and flanged fittings are subject to stress both from (3)

Answer 71

1. internal pressure 2. mechanical loadings and temperature changes. 3. closing stresses and stress concentrations because of their shape.

Question 72

Reduction of strength of the metal in a pipe, scaling, bulging, metal deterioration or complete failure are all symptoms of:

Answer 72

excessive temp

Question 73

Points of probable external corrosion of underground piping can be located by a series of measurements of the

Answer 73

electrical (soil) resistance of surrounding soil or by measurement of pipe-to-soil electrical potential.

Question 74

A weld is being made in carbon steel piping carrying Amine (MEA). What should the inspector check in addition to insuring that the weld is proper and meets specifications

Answer 74

Amine can cause environmental cracking; the weld should be checked for hardness.

Question 75

Welded joints in carbon steel and carbon-molybdenum steel exposed to elevated temperatures of 800degrees F or over may be subject to

Answer 75

graphitization.

Question 76

_____of piping in high-temperature service—metal temperatures of about 800 °F (427 °C) and above—should be measured to check for creep or deformation with time under stress.

Answer 76

The OD

Question 77

Special attention should be given to small connections such as vents, bleeders, any type of small nipple. One method for successfully checking the condition and the thickness of nipples is the use of:

Answer 77

RT

Question 78

A pressure test of piping, in most cases is a:

Answer 78

leak test

Question 79

What should be considered when testing carbon steel piping during cold weather or if cold fluids are used in the testing?

Answer 79

The transition temperature of the steel should be considered to prevent brittle failure.

Question 80

Which of the following piping should NOT be hammer tested? (material and what service)

Answer 80

cast iron and stress-relieved lines in caustic and corrosive service.

Question 81

Important points for consideration when using a soil box include: (3)

Answer 81

a) avoiding contamination during soil sample removal, handling, and storing; b) avoiding adding or subtracting water; c) having to compact the soil sample to the same density in the soil box as it was prior to removal from the ground.

Question 82

The following conditions should be considered in four-pin soil resistivity measurements: (4)

Answer 82

a) all underground structures should be excluded from the measurement, b) all of the pins should be in a straight line and equally spaced, c) the depth of the pins inserted into the ground should be less than 4 % of the spacing, d) the soil resistivity meter should be designed to exclude any effect of extraneous AC or DC currents.

Question 83

Suggestions for use of the soil bar include: (3)

Answer 83

a) use of a standard prod bar to provide the initial hole; b) avoiding addition of water during, or after opening the hole; c) applying pressure on the soil bar after insertion into the open hole

Question 84

Wenner Four-pin Method

Answer 84

resistivity (ohm-cm) = 191.5 x d x R d= feet

Question 85

at what temp does sulfidation on CS occurs

Answer 85

500 F

Question 86

Special attention should be given to low-alloy steels (especially 21/4 Cr-1 Mo material), because they can be

Answer 86

prone to temper embrittlement, and to ferritic stainless steels.

Question 87

creep cracking has been experienced in the industry is in 1 1/4 Cr steels above

Answer 87

900 °F (482 °C).

Question 88

Special delay-line materials and water-cooled transducers are available that permit the use of pulse-echo instruments at temperatures up

Answer 88

to 1100 °F

Question 89

A close-interval pipe-to-soil potential survey measures the potential of the pipe to the soil directly over the pipe, at predetermined intervals between measurements, usually at

Answer 89

2.5 ft, 5 ft, 10 ft, or 20 ft

Question 90

Creep is dependent on

Answer 90

time, temperature, and stress.

Question 91

NDE for environmental cracking? (4)

Answer 91

1. PT 2. WFMT 3. UT 4. eddy current (ET).

Question 92

bulges or staining of the insulation or jacketing system or missing bands is what damage mechanism?

Answer 92

CUI

Question 93

Gate valves should be measured for thickness _________, since turbulence can cause serious deterioration

Answer 93

between the seats

Question 94

bulges at insulation can indicate

Answer 94

corrosion product buildup

Question 95

Gate valves - Reduced port valves should not be used as block valves associated (3)

Answer 95

with pressure-relief devices (PRDs) or in erosive applications, such as slurries, or lines that are to be “pigged.”

Question 96

injection point examination

Answer 96

12 feet upstream , and 10 pipe diameters downstream

Question 97

one quarter turn valve?

Answer 97

1. plug 2. ball 3. butteryfly

Question 98

For services with high potential consequences if a failure were to occur, the piping engineer should consider increasing the

Answer 98

minimum allowed thickness

Question 99

if buried piping has CP, when is excavation required?

Answer 99

when evidence of wrap or coating has failed

Question 100

FRP piping include service

Answer 100

water, process water, cooling medium, potable water, sewage/gray water, nonhazardous waste, nonhazardous drains, nonhazardous vents, chemicals, firewater ring mains, firewater deluge systems, and produced and ballast water.

Question 101

gates valve another name is

Answer 101

block valve

Question 102

gate valve are not used for

Answer 102

regulating flow

Question 103

globe valve are used for

Answer 103

regulating flow

Question 104

For fine-throttling service, a very steep tapered seat can be used; this particular type of globe valve is referred

Answer 104

to as a needle valve.

Question 105

Plug valves can be operated by a . ____. What other valve like this too?

Answer 105

gear-operated device or by turning a wrench on the stem / ball valve

Question 106

Plug valves are either

Answer 106

lubricated or nonlubricated;

Question 107

Plug valves usually function as ____. What other valves are like this?

Answer 107

block valves to close off flow (like gate valves and ball valves)

Question 108

the slide valve is a specialized gate valve generally used in

Answer 108

erosive or high-temperature service. I

Question 109

Periodic temperature monitoring via visual, infrared, temperature indicating paints should be undertaken on these types of lines to confirm the integrity of the

Answer 109

refractory

Question 110

injection point NDE

Answer 110

RT/ UT

Question 111

what valve would make it impossible to pig a line

Answer 111

globe valve

Question 112

type of valve should not be used if pig a line (4)

Answer 112

1. reduce port gate valve 2. plug valve 3. butterfly valve 4. globe

Question 113

what type of valves to use with pigging (2)

Answer 113

gate valves / ball / slide

Question 114

generally piping is replaced or repaired when it reached

Answer 114

min thickness requirement

Question 115

schedule 40s , S =?

Answer 115

stainless steel

Question 116

The corrosion rate in _______ can vary significantly from adjacent active piping

Answer 116

dead-legs

Question 117

buried piping uncoated should consider excavating

Answer 117

6-12 inches

Question 118

secondary piping is isolated from

Answer 118

main process lines

Question 119

The external condition of buried piping that is not cathodically protected should be determined by either

Answer 119

pigging, or excavating

Question 120

lengths greater than 100 ft (30 m) and not cathodically protected, evaluations of soil corrosivity should be performed at appropriate intervals

Answer 120

based on likelihood of change

Question 121

leak test for burried piping

Answer 121

8 hours