Field Guide chpt 1-3

Question 1

Who should develop an investigative plan for an internal pipeline corrosion failure?

Answer 1

A team

Question 2

Which visual appearance may indicate the effects of historical liquid levels in the pipeline?

Answer 2

Corrosion in longitudinal bands along both sides of the pipe.

Question 3

Which internal pipeline condition most indicates hydrogen sulfide presence.

Answer 3

Odor similar to rotten eggs

Question 4

When collecting physical evidence of internal corrosion, cleaned pipe should be used primarily for

Answer 4

Dimensional analysis

Question 5

Which type of physical evidence is intended to capture the deposits and bio-film and their relation to corrosion?

Answer 5

Embedments

Question 6

Concentration cell corrosion within small areas isolated from the bulk fluid stream.

Answer 6

Crevice Corrosion at Joints

Question 7

General etching over large continuous areas that still contain isolated pitting or clusters of pits

Answer 7

Isolated Pitting within General Corrosion

Question 8

Combined action of corrosion and metal loss due to rapidly moving fluids and/or solid particles.

Answer 8

Erosion Corrosion

Question 9

Numerous small pits growing together or a few large pits that connect only after they have grown to a certain size.

Answer 9

Interconnected Pitting

Question 10

Mechanisms which include SCC, corrosion fatigue, SSC, HIC, etc.

Answer 10

Environmental Cracking

Question 11

Etching or near uniform attack with just a few scattered pits.

Answer 11

General Metal Loss with Infrequent Pits

Question 12

Special features such as cup-type hemispherical pits, pits within pits, striations parallel to the longitudinal axis of the pipe, tunnels in the end walls of pits, etc.

Answer 12

Unique Pit Morphology

Question 13

Uniform attack of the pipe wall.

Answer 13

Etching or General Loss with No Pitting

Question 14

Pits occur singularly or in groups but the pits are not interconnected.

Answer 14

Isolated Pitting

Question 15

Preferential attack of the weld metal or heat affected zone of the parent metal.

Answer 15

Selective Attack at Welds

Question 16

measurement of the deepest pit depth and the average pit depth.

Answer 16

Maximum/Average pit depth

Question 17

Measurement of wall thickness every .25 inches along the longitudinal axis in the deepest areas of interconnected corrosion.

Answer 17

Profile of wall loss

Question 18

Measurement of the deepest corrosion or thinnest wall caused by corrosion.

Answer 18

Maximum wall loss

Question 19

Measurement of the greatest pit diameter and average pit diameter.

Answer 19

Maximum/average Pit diameter

Question 20

Examining the typical length and width of pits to determine if there is a preferred orientation to the pitting.

Answer 20

Pit length Vs. Pit width

Question 21

A description of how far the corrosion is present about the circumference of the pipe.

Answer 21

Circumferential extent

Question 22

A description of how far the corrosion extends down the longitudinal axis of the pipe.

Answer 22

longitudinal extent

Question 23

Calculation of both average depth/average diameter and maximum depth/maximum diameter ratios.

Answer 23

Depth/Diameter ratio

Question 24

list the 5 factors other than morphology or physical appearance that should be considered by a competent corrosion investigator before making a conclusion.

Answer 24

1  chemistry
2  electro-chemistry
3 microbiology
4  metallurgy
5  physical condition (temp, flow velocity, etc)

Question 25

list 3 main areas of managing internal corrosion of pipelines

Answer 25

1 detecting the corrosion
2 determining the cause of the corrosion
3 mitigating (controlling) corrosion

Question 26

this text is concerned with

Answer 26

determining the cause of corrosion

Question 27

The six “Who” questions that are essential to an investigative plan

Answer 27

1 who will do the investigative work.

2 who will collect samples both at the investigating site
and at the gas/liquid source.

3 who is responsible for documenting the investigation
and writing a report.

4 who will decide if outside lab services are needed.

5 who will stock and maintain testing supplies for future.

6 who needs to receive info about the investigation.

Question 28

list the 4 “What” questions that must be answered for an investigative plan.

Answer 28

1 what types of testing will be conducted immediately in the field and later in the lab

2 What samples must be collected

3 What tools and supplies are needed to perform the testing and preserve any samples collected

4 what are the relevant health and safety issues associated with a field investigation.

Question 29

list the 3 “Where” questions essential to an investigative plan.

Answer 29

1 Where will investigation be performed.

2 Where will field investigation supplies be stored for quick access.

3 Where do samples need to be sent for analysis.

Question 30

List the 3 “When” questions for an investigative plane.

Answer 30

1 When are the company “corrosion detectives” called in on the scene.

2 When are certain types of tests performed

3 when or how quickly does the cause of corrosion need to be determined.

Question 31

The “Why” question that must be determined when developing an investigative plan

Answer 31

Why are we conducting the investigation.

Question 32

List the 2 “How” questions that must be determined when developing an investigative plan.

Answer 32

1 How do we collect and analyze chemical and biological samples.

2 How does one interpret test data and reach a conclusion.

Question 33

what are 3 general regulatory areas to consider when complying with state, federal, and other jurisdiction regulations.

Answer 33

1 human health and safety
2 environmental impact
3 operational compliance

Question 34

three main categories of evidence to consider when gaining a perspective on internal pipeline corrosion.

Answer 34

1 visual evidence

2 physical evidence

3 circumstantial evidence

Question 35

5 measurement tools the author suggests to collect measurable visual evidence.

Answer 35

1 steel tape measure

2 small finely divided steel ruler

3 pit gauge

4 pipe micrometer

5 ultrasonic thickness gauge.