Inhibitors Flashcards
Scale formation over the entire surface. Most common types: Silicates Phosphates
Precipitation inducing Inhibitors
AKA Gunkers
Ohmic inhibitors
AKA volatile corrosion Inhibitors Inhibitors is vaporized into a gaseous form Inhibits corrosion by making the environment alkaline
Vapor Phase Inhibitors
Can reduce the effectiveness of inhibitors
Bicarbonates Metal cations
The corrosion Investigator’s first job on-site is to:
Protect all evidence
the Corrosion Investigator’s second job on-site is to:
Collect all evidence
The presence of water can be confirmed in a sample by using ….
Hydrion paper
Which gas analysis test cannot be collected with a stain tube?
Pressure
A procedure that penetrates and preserves the scale, corrosion product, microbes and deposits that are present on an internally corroded pipe is:
Embedment
The temperature of liquid samples is measured in the field using:
Common laboratory thermometer and with an electronic temperature probe.
The pH of aqueous samples is measured using:
pH Meter and pH Test Paper
These samples must be taken where there are differences in color, texture, density or composition of materials in the pipe
Solid/Sludge sampling
These samples are normally collected in stainless steel sample bottles or Tedlar bags. Stain tubes can sometimes be used to replace some samplings.
Gas Sampling
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.
Liquid Sampling
This sample should be cut using a portable band saw or wheel-type cutter to prevent torch cutting debris from entering the sample.
Pipe Sampling
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.
XRD - X-Ray Diffraction (XRD)
This method provides elemental compositional analysis of very thin (3nm) surface layers.
AES - Auger Electron Spectroscopy
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.
FTIR and Raman Spectoscopy
A long established technique used to identify nearly 70 diff elements in liquid and solid samples down to parts per billion.
Atomic Absorption
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.
Gas or Liquid Chromatography
These 2 methods can quantitatively identify over 70 elements in liquids, solids and particulates. They provide shorter analysis times than AAS.
DCP/ICP - Direct Current Plasma & Inductively Coupled Plasma
This procedure uses liquid chemistry data to calculate values which are simply indications as to the propensity for
Scaling Index
This term describes laboratory analysis techniques such as gravimetry, titrimetry and numerous separation methods. It is time consuming and methods vary widely
Wet Chemistry
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
Ion Chromatography
