ASTM D130 Copper Strip Corrosion Tester Significance and method

The copper corrosion tester is designed and made according to ASTM D130. It is suitable for the determination of aviation gasoline, jet fuel, motor gasoline, natural gas or other hydrocarbons with Reid vapor pressure not greater than 124 kPa (930 mm Hg), and solvent oil, diesel, distillate fuel oil, lubricating oil and other petroleum products to the extent of copper corrosion.

Why measure copper corrosion in petroleum products? Because crude oil contains acid, most products produced from crude oil have a certain degree of acidity (corrosion). Copper corrosion is to measure the corrosiveness of petroleum  products; different indicators are used for different levels of terminals, such as: The corrosiveness in liquefied gas is slightly corrosive to steel equipment, and it has a melting effect on rubber. There are plastic pipes at the terminals of filling liquefied gas, which are highly corrosive and will definitely cause danger.

The following is a detailed introduction to the test method of the copper corrosion tester:

The copper sheet corrosion equipment is used to determine the corrosiveness of diesel oil, gasoline, lubricating oil or other petroleum products to copper. This method involves flammable materials. Before operation, pay attention to the ignition point and flash point of the sample, and pay attention to safety during operation.

Preparation of copper sheets:

1. Use the clamp to clamp the copper sheet longitudinally. First, use relatively coarse sandpaper (the lower the mesh, the thicker the sandpaper) to remove the defects of the copper sheet. You can change the direction of the copper sheet on the clamp back and forth to make the six sides of the copper sheet. The flaws on all parts and the traces of previous grinding are removed. After grinding, the metal chips on the copper sheet can be wiped off with a quantitative filter paper. At this time, the copper sheet can be washed in a washing solvent, dried and then polished. The final polishing can also be carried out directly. The polished copper sheets should be taken with tweezers or filter paper, and should not be touched by hand.

2. Grind the copper sheet with sandpaper with a higher mesh or use absorbent cotton dipped in sand to polish the surface of the copper. When grinding, try to polish along the long axis of the copper sheet.

3. After the copper sheet is polished and brightened, wipe off the metal chips with absorbent cotton. After the copper sheet is wiped clean, put it into the prepared sample.

Experimental procedure:

1. Sampling: Take 30 ml of sample and pour it into the test tube. The sample should be stored in a clean, dark glass bottle as much as possible. The test tube should be dry and clean.

2. Different samples use different test steps:

    A. Lubricating oil, solvent oil, kerosene: Measure 30 ml of a sample that is completely clear, without suspended water or contained water, and pour it into a clean, dry test tube with a test tube clamp, and put the final polished and clean copper sheet In the sample put into the test tube, put the test tube with the test tube clamp into the bath that has been maintained at 100±1°C, put it in the bath for 3±5 hours, take out the test tube, and check the copper piece.

    B. Aviation gasoline and jet fuel: Measure 30 ml of a completely clear sample with no suspended water or water in it, pour it into a clean, dry test tube, carefully slide the test tube into the test bomb, and screw the cap tightly. , Put the test bomb completely into the bath that has been maintained at 100±1℃, put it in the bath for 2±5 hours, take out the test bomb, rinse it with tap water for a few minutes, open the test bomb, take out the test tube, and check the copper sheet.

    C. Natural gasoline: Measure 30 ml of a completely clear sample with no suspended water or water in it, pour it into a clean and dry test tube, carefully slide the test tube into the test bomb, screw the cap tightly, and put the test tube into place. Put the bomb completely into the bath that has been maintained at 40±1℃, put it in the bath for 2±5 hours, take out the test bomb, rinse it with tap water for a few minutes, open the test bomb, take out the test tube, and check the copper sheet

    D. Diesel oil, fuel oil, motor gasoline: Measure 30 ml of a sample that is completely clear, without suspended water or water in it, and pour it into a clean, dry test tube with a test tube clamp. Put the test tube into the sample of the test tube, put the test tube with the test tube clamp into the bath that has been maintained at 50 ± 1 ℃, put the test tube in the bath for 3 ± 5 hours, take out the test tube, check the copper sheet

Inspection of copper sheets

1. Take out the copper sheet with tweezers, wash the sample with washing solvent, or wipe the sample on the copper sheet with filter paper, do not touch the copper sheet with your hands

2. Put the copper sheet into the flat observation tube to prevent the clamped copper sheet from leaving stains and stains during inspection and comparison.

3. Compare the copper sheet with the corrosion standard color plate. When comparing, try to hold the copper sheet and the corrosion standard color plate in a 45° refraction way to observe the light.

4. Determine the corrosivity of the sample according to the classification of the corrosion standard color plate

Grading of Corrosion Standard Swatches:

Instructions for judging corrosiveness:

1. When the corrosion level of the copper sheet is between two adjacent standard color plates, judge the sample according to the corrosion level with severe discoloration

2. When the copper sheet has a darker orange than 1b in the standard color plate, it is considered that the copper sheet is still grade 1, but if red is observed, the copper sheet is judged to be grade 2.

3. The purple copper sheet in grade 2 may be mistaken for grade 3, where the brass color is completely covered by magenta. Orange, grade 3 does not change color

4. If the copper sheet is dirty during the heating and leaching process, it needs to be tested again

5. If there is a corrosion level higher than the corrosion level of most of the surface of the copper sheet along the edges and corners of the plane of the copper sheet, it is necessary to re-test

6. If the two results of the repeated measurement are not the same, re-test the test. When the two results of the re-test are still different, judge the sample according to the corrosion grade with severe discoloration.