Chloride contamination of line pipe: Its effect on FBE coating performance
- Harding and Neal Inc., Houston, TX (United States)
- Energy Coatings Inc., Houston, TX (United States)
Two pipes were contaminated with various levels of chloride. One pipe was coated without removing the contamination; the other was coated after decontamination with phosphoric acid. A third pipe, not contaminated, was treated with phosphoric acid before coating. Chloride levels were measured using an extraction sampling technique and ASTM D 512 Method A for analysis. Residual phosphorus was also measured using an x-ray fluorescence procedure. Hot cathodic disbonding resistance is adversely affected in direct proportion to the level of chloride contamination. The data suggest a maximum level of 2.0 {micro}g/cm{sup 2} measured by extraction on a blast-cleaned surface is essential for good coating performance. Residual phosphorus levels may adversely affect cathodic disbonding but appear to enhance water resistance. Data on the accuracy of the chloride measurement procedure is presented together with information on other methods for determining chloride.
- OSTI ID:
- 87683
- Journal Information:
- Materials Performance, Journal Name: Materials Performance Journal Issue: 2 Vol. 34; ISSN MTPFBI; ISSN 0094-1492
- Country of Publication:
- United States
- Language:
- English
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