Inhibitors

Question 1

AKA Gunkers

Answer 1

Ohmic inhibitors

Question 2

Scale formation over the entire surface. Most common types: Silicates Phosphates

Answer 2

Precipitation inducing Inhibitors

Question 3

AKA volatile corrosion Inhibitors Inhibitors is vaporized into a gaseous form Inhibits corrosion by making the environment alkaline

Answer 3

Vapor Phase Inhibitors

Question 4

Can reduce the effectiveness of inhibitors

Answer 4

Bicarbonates Metal cations

Question 5

The corrosion Investigator’s first job on-site is to:

Answer 5

Protect all evidence

Question 6

the Corrosion Investigator’s second job on-site is to:

Answer 6

Collect all evidence

Question 7

The presence of water can be confirmed in a sample by using ….

Answer 7

Hydrion paper

Question 8

Which gas analysis test cannot be collected with a stain tube?

Answer 8

Pressure

Question 9

A procedure that penetrates and preserves the scale, corrosion product, microbes and deposits that are present on an internally corroded pipe is:

Answer 9

Embedment

Question 10

The temperature of liquid samples is measured in the field using:

Answer 10

Common laboratory thermometer and with an electronic temperature probe.

Question 11

The pH of aqueous samples is measured using:

Answer 11

pH Meter and pH Test Paper

Question 12

These samples must be taken where there are differences in color, texture, density or composition of materials in the pipe

Answer 12

Solid/Sludge sampling

Question 13

These samples are normally collected in stainless steel sample bottles or Tedlar bags. Stain tubes can sometimes be used to replace some samplings.

Answer 13

Gas Sampling

Question 14

Collect at least 500ml in two 250 ml sample containers at the site of the cut if possible. Samples should be filled to the top to exclude air and capped.

Answer 14

Liquid Sampling

Question 15

This sample should be cut using a portable band saw or wheel-type cutter to prevent torch cutting debris from entering the sample.

Answer 15

Pipe Sampling

Question 16

Common technique used to identify crystalline phases in unknown materials. These crystalline phases are described as compounds rather than elements which is beneficial in understanding corrosion.

Answer 16

XRD - X-Ray Diffraction (XRD)

Question 17

This method provides elemental compositional analysis of very thin (3nm) surface layers.

Answer 17

AES - Auger Electron Spectroscopy

Question 18

These two methods are used with microscopes to examine small areas or features. Both methods usually allow mapping of the surface and are used for bulk sample analysis.

Answer 18

FTIR and Raman Spectoscopy

Question 19

A long established technique used to identify nearly 70 diff elements in liquid and solid samples down to parts per billion.

Answer 19

Atomic Absorption

Question 20

This method is used to look for corrosion inhibitors, biocides, methanol, glycol and organic materials but the investigator must have some idea of the organic material for which they are searching.

Answer 20

Gas or Liquid Chromatography

Question 21

These 2 methods can quantitatively identify over 70 elements in liquids, solids and particulates. They provide shorter analysis times than AAS.

Answer 21

DCP/ICP - Direct Current Plasma & Inductively Coupled Plasma

Question 22

This procedure uses liquid chemistry data to calculate values which are simply indications as to the propensity for

Answer 22

Scaling Index

Question 23

This term describes laboratory analysis techniques such as gravimetry, titrimetry and numerous separation methods. It is time consuming and methods vary widely

Answer 23

Wet Chemistry

Question 24

This is a popular method for determining the concentrations of ionic species in aqueous samples. Typical results would identify sulfate, sulfite, nitrate, nitrite, phosphate, chloride, bromide and floride

Answer 24

Ion Chromatography

Question 25

Pair of tests are some of the most popular techniques used for examining and analyzing elemental surface components of corrosion-related samples.

Answer 25

SEM/EDS - Scanning Electron Microscopy/Energy Dispersive Spectroscopy

Question 26

This technique is used more frequently in the study of microorganisms than of corrosion.

Answer 26

TEM - Transmission Electron Microscopy

Question 27

This method is like Auger as another method that analyzes atomic surface layers for elemental composition. It is more sensitive and has better spatial resolution than EDS

Answer 27

SIMS - Secondary Ion Mass Spectroscopy

Question 28

What is the final and most important part of instituting a corrosion mitigation program?

Answer 28

Monitoring the effectiveness of the treatment

Question 29

Step # 1

Answer 29

Physically arrange the investigation results in logical progression

Question 30

Step # 2

Answer 30

Ask the 20 Questions

Question 31

Step # 3

Answer 31

Look for the connections between the different types of data.

Question 32

Step # 4

Answer 32

Develop a factual story of what happened to cause the failure using the results, observation and relationships.

Question 33

Step # 5

Answer 33

Put the finding in writing.

Question 34

Three methods for mitigating internal corrosion once the cause has been identified?

Answer 34

Remove the environment that provided corrosion. Change internal environment by altering operations or maintenance procedures, Chemical treatment with inhibitors.

Question 35

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

Answer 35

A Team

Question 36

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

Answer 36

Corrosion in the longitudinal bands along both sides of the pipe

Question 37

Which internal pipeline condition most indicates H2S presence?

Answer 37

Rotten egg smell

Question 38

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

Answer 38

Dimensional Analysis

Question 39

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

Answer 39

Embedments

Question 40

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

Answer 40

Crevice Corrosion at Joints

Question 41

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

Answer 41

Isolated pitting with General Corrosion

Question 42

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

Answer 42

Erosion Corrosion