Copper Corrosion Analyser

Copper Corrosion Analyser

ASTM D130

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The Copper Strip Tarnish Test assesses the relative degree of corrosivity of petroleum products, including aviation fuels, automotive gasoline, natural gasoline, solvents, kerosene, diesel fuel, distillate fuel oil, lubricating oil and other products. A polished copper strip is immersed in 30mL of sample at elevated temperature. After the test period, the strip is examined for evidence of corrosion and a classification number from 1-4 is assigned based on a comparison with the ASTM Copper Strip Corrosion Standards. For aviation fuels and natural gasoline the sample tube is placed inside a stainless steel bomb during testing.


Copper Strip Corrosion Test Bomb

Precision machined stainless steel bomb inserts in copper corrosion bath for testing aviation fuels and natural gasoline. Withstands test pressure of 100psi (689kPa) per specifications. Threaded cap with O-ring gasket and knurled circumference tightens by hand to a positive seal. A 1/8 groove in the bomb threads permits safe, gradual release of pressure when opening the bomb.


Why we need to know?

  • Corrosion is the gradual destruction of materials, (usually metals), by chemical reaction with its environment.
  • In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen. Rusting, the formation of iron oxides, is a well-known example of electrochemical corrosion. This type of damage typically produces oxide(s) or salt(s) of the original metal. Corrosion can also occur in materials other than metals, such as ceramics or polymers, although in this context, the term degradation is more common. Corrosion degrades the useful properties of materials and structures including strength, appearance and permeability to liquids and gases.
  • Many structural alloys corrode merely from exposure to moisture in air, but the process can be strongly affected by exposure to certain substances. Corrosion can be concentrated locally to form a pit or crack, or it can extend across a wide area more or less uniformly corroding the surface. Because corrosion is a diffusion-controlled process, it occurs on exposed surfaces. As a result, methods to reduce the activity of the exposed surface, such as passivation and chromate conversion, can increase a material’s corrosion resistance. However, some corrosion mechanisms are less visible and less predictable.
  • Copper occurs naturally with elements such as lead, nickel, silver and zinc. It is widely used in industry both as a pure metal and as an alloy material. The copper industry is composed of two segments: producers (mining, smelting and refining industries) and fabricators (wire mills, brassmills, foundries and powder plants). The end products of copper producers, the most important of which are refined cathode copper and wire rod, are sold almost entirely to copper fabricators. The end products of copper fabricators can be generally described as mill products and foundry products, and they consist of wire and cable, sheet, strip, plate, rod, bar, mechanical wire, tubing, forgings, extrusions, castings and powder metallurgy shapes. These products are sold to a wide variety of industrial users.
  • The resistance of all grades of copper to atmospheric corrosion is good, hence their wide usage for roofing and for contact with most waters. The metal develops adherent protective coatings, initially of oxide, but subsequently thickening to give a familiar green patina on roofs and the dark brownish color of bronze statuary. Because copper is largely unaffected by potable water, it’s widely used for tubes carrying domestic and industrial water. In the following broad classifications, copper and copper alloys have demonstrated superior corrosion performance:
  • Atmospheric exposure such as roofing and other architectural applications.
  • Plumbing systems with superior corrosion resistance to both potable waters and soils.
  • Marine applications involving supply lines, heat exchangers, and hardware where ance resist to seawater and biofouling are mandatory.
  • Industrial and chemical plant process equipment involving exposure to a wide variety of organic and inorganic chemicals.
  • Regarding the use of hydrochloric acid or muriatic acid for cleaning copper.
  • The oxides of copper are quite soluble in hydrochloric acid. You end up with what is called a "salmon" color. Copper metal will not dissolve in HCl so it is a safe way to clean with a solution which is easy to rinse.
  • There is a hook (as usual) IF there is dissolved oxygen in the acid then copper metal will go into solution. This not a problem for a quick clean but if you leave the copper in the acid for a long period of time you will dissolve copper and it will be particularly noticeable at the acid air interface where the oxygen concentration is highest.


Copper Corrosion for General Oil and Pentas Flora Recovered Oil:


General Oil

Appearance

Base Oil

Slight Tarnish

Bunker Fuel

Dark Tarnish

Diesel

Slight Tarnish

Heavy Oil

Moderate Tarnish

Light Fuel Oil 80 cSt

Slight Tarnish

Medium Fuel Oil 180 cSt

Slight Tarnish

Tyre Oil

Moderate Tarnish

Waste Engine Oil

Moderate Tarnish

Pentas Flora Recovered Oil

Appearance

Eco Light Fuel Oil

Dark Tarnish

Super Light Fuel Oil

Slight Tarnish

Green Light Fuel Oil

Dark Tarnish

Base Light Fuel Oil

Dark Tarnish