June 3 - June 7, 2019
What is the maximum number of holidays that should be permitted for linings used in immersion service, and why?
Selected Answers
From
Zenith Czora of Parex Davco on
June 6, 2019:
There should be no holidays or pinholes allowed for linings used in immersion services. Those holidays or pinholes will allow passage of any liquid or vapors to penetrate into the substrate. Those entrapped liquids or vapors slowly affect the integrity of the substrate and will lead to structural deterioration.
From
Bill Slama of International Paint/Ceilcote Products on
June 6, 2019:
I agree with Larry. Some of the chemicals that could be in the tanks are extremely corrosive to steel and a pinhole could result in a perforation all the way through the steel in days.
If the question is how many pinholes are allowed to be repaired, I am not aware that that has ever been established. In some cases, if the applied lining system has an extremely great number of pinholes, I would recommend an additional layer of lining before continuing the testing.
From
trevor neale of TF Warren Group on
June 4, 2019:
Unless the procurement allows, then the lining should be completely free from pin holes and any other type of discontinued coating.. ..
From
Ricardo Márceles of Pintuco on
June 4, 2019:
When carrying out an inspection with a holiday detector, the thickness of the film applied should be taken into account in order to determine the voltage of the equipment. When doing the revision, with the recommended speed, the points to be corrected are located; this is a job that requires a lot of concentration, Therefore, it is NOT necessary, nor should a new revision be made with the holiday detector. Check that effectively ALL DETECTED POINTS have been repaired.
From
Larry Muzia of Exceletech Coating & Applications, LLC on
June 3, 2019:
I am a believer that NO pinholes or holidays should be allowed in immersion. The long and short answer--it is a defect, in what should be a properly adhered, properly applied and cured immersion grade lining. An exposed area will set up a corrosion cell.
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Tagged categories:
Asia Pacific;
Coating Application;
EMEA (Europe, Middle East and Africa);
Holidays;
Latin America;
North America
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