A.W. Chesterton Company ARC Division

860 Salem Street, Building A Groveland, MA 01834 USA

Technical Report Date: June 12, 2002 From: Joseph E. Veilleux, P.E., Senior Applications Engineer Muni Ramakrishnan, Ph.D., Senior Research Scientist To: Test Laboratory File Subject: Corrocell and Soak Test Summary for ARC S1 versus Belzona 5811 in 10% Sulfuric

Acid (H2SO4) at 50 oC. Executive Summary

This report documents the results of benchmark testing performed between ARC S1 and Belzona 5811 in 10% H2SO4 solution at 50oC. The results of the test qualify ARC S1 for long term immersion in 10% H2SO4 (“1” rating), which is the maximum concentration present in the bottom of heavy crude oil storage tanks. ARC S1 previously was rated for short-term immersion only (“2” rating) in 10% H2SO4 and would not be accepted by petroleum refineries with this requirement. The test program included Corrocell and soak testing of ARC S1 and Belzona 5811, a competitive product frequently specified for crude oil and other petroleum fuel tank lining applications, over a fourteen-week test period. The testing concluded that in addition to being qualified for long term immersion in 10% H2SO4, that ARC S1 exhibited vastly superior performance in this environment as compared to the competitive Belzona product.

Background

The subject Corrocell and soak testing was performed at the A.W. Chesterton Company ARC Research Center Laboratory in Groveland, MA, USA between February 18 to June 7, 2002. The purpose of the test was to evaluate the resistance of ARC S1 to chemical attack and blistering in a 10% H2SO4 immersion environment at 50oC. Belzona 5811 Immersion Grade, a competitive tank lining product, was also evaluated in this benchmark test program.

ARC S1 is rated for long term immersion in crude and other petroleum oil products.

However, certain heavy crude oils, such as those extracted in Venezuela, can contain up to 10%

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H2SO4. When the crude oil is pumped into large storage tanks awaiting refining, the entrained sulfuric acid settles on the bottom of the tank due to the aqueous acid solution having a higher density than the crude oil. This creates an aggressive service environment equal to continuous exposure to 10% H2SO4 at ambient temperature with cold wall effect. References 1. ARC S1 Product Data Sheet. 2. Belzona 5811 Immersion Grade – Instructions for Use. 3. Chemical Resistance Chart for ARC Composites. Test Description

Soak and Corrocell testing of ARC S1 and Belzona 5811 was performed in accordance with

approved A.W. Chesterton Company, Technical Products Division ISO 9001 laboratory procedures. The soak test procedure is based on NACE Standard TM0196-96. The Corrocell test meets the requirements of ASTM C 868 and other international test standards.

Soak testing included making three specimen pucks each of ARC S1 and Belzona 5811, and

immersing them in 10% H2SO4 solution at 50oC, after 7-day ambient cure. Prior to the start of the test, each puck was weighed and the color and general appearance was noted. Every seventh day, the pucks were removed from the acid solution and re-weighed. Any change in color and visual appearance of the puck as well as the acid solution was also recorded. The percent of weight gain or loss was then recorded for each specimen.

The Corrocell test procedure consisted of coating three panels each of ARC S1 and Belzona 5811. Two coats were applied per panel to the specified thickness in the respective Product Data Sheets. After 7-day ambient cure, the panels were tested in Corrocell chambers – two panels per chamber.

The liquid temperature was maintained at 50oC +/- 0.5oC, by means of a computerized heat

control system. Once a week, the panels in each chamber were inspected for evidence of blister attack and discoloration. The liquid color and appearance (cloudiness etc.) were also noted.

Observations

1) During the soak test, the Belzona 5811 specimen pucks severely discolored the sulfuric acid solution, resulting in a cloudy, dark, oily liquid. It appeared that the acid attack on Belzona 5811 caused the oily liquid formation. The soak test therefore was stopped after six weeks. 2) The average percent weight gain measured on the Belzona 5811 pucks in 4 weeks was 4.9% and, in six weeks was 8.3% (See Figure 1). 3) In contrast, the corresponding numbers for ARC S1 were 2.2% and 3.7% respectively (See Figure 1).

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Figure 1 – ARC S1 and Belzona 5811 Soak Test Data

4) For the ARC S1 specimens, the soak acid solution was clear and colorless after 6 weeks. 5) During the Corrocell testing, all of the Belzona 5811 panels blistered in three weeks. The blisters grew in size during the balance of the fourteen-week test period, resulting in the coating practically delaminating from the substrate at the conclusion of the test. 6) The normally black Belzona 5811 changed color to a light tan in the Corrocell chamber immersion zone after several weeks’ exposure to the test liquid. Figures 2 and 3 illustrate the blister formation on the Belzona 5811 panels at the conclusion of the test. Figure 4 shows the onset of a corrosion cell with crystallized material on the reverse side of the blister.

Figure 2 – Belzona 5811 Corrocell panel exhibiting blister attack.

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Figure 3 – Second Belzona 5811 Corrocell panel exhibiting blister attack.

Figure 4 – Reverse side of Belzona 5811 blister. 7) All three ARC S1 panels completed the fourteen-week test program with no evidence of blistering. 8) The original ARC S1 Blue experienced discoloration to a light tan color in the Corrocell chamber immersion zone. However, a color change alone does not indicate that chemical attack has occurred. For ARC S1 exposed to 10% H2SO4 at 50oC, discoloration of this nature would be anticipated. Figure 5 illustrates the ARC S1 panel taken from chamber 2, at the conclusion of the test. 9) The two ARC S1 panels in chamber 1 are still under test and continue to perform well after seventeen weeks.

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Figure 5 – ARC S1 Corrocell panel after fourteen weeks of exposure.

Overall Conclusions 1) The soak test numbers over a six week period and the promising Corrocell run without any

blisters over a 14 + week period indicate that ARC S1 is suitable for continuous immersion in 10% H2SO4 solution. This is based on our acceptance criteria established on a large number of lab and field test data.

2) By the same token, the Belzona 5811 soak numbers as well as Corrocell data clearly shows that it is a far inferior product. Based on the same acceptance criteria, our conclusion is that Belzona 5811 is unacceptable for continuous immersion in 10% H2SO4 solution and not suitable for crude oil or petroleum product tank linings.

Joseph E. Veilleux, P.E. Senior Applications Engineer Muni Ramakrishnan, Ph.D. Senior Research Scientist