Salt soluble test for un-coated surface
Salt soluble test for un-coated surface
(OP)
Good morning Gents,
We have hydrotested our tanks with ground water where high Chloride concentrate (more than 10000 ppm) is in the water.
The interior of our tanks would be coated only bottom plate + 1 M of shell from the bottom. The rest would be no blasting nor coating.
After washing down the interior surface of the tank with a good quality water our painting subcontractor only check the salt soluble on the area that would be coated. They did not check the other area. Yes they did use high pressure pump during washing. But I am not sure the cleanliness on the top side. They did not use a scaffolding during washing.
The salt content on area that would be coated are within tolerance. So they assume it would be the same for other area. They don't want to build a scaffolding to check the area above 1 M.
Do you think this is acceptable ?
Your comments and advise is highly appreciated.
We have hydrotested our tanks with ground water where high Chloride concentrate (more than 10000 ppm) is in the water.
The interior of our tanks would be coated only bottom plate + 1 M of shell from the bottom. The rest would be no blasting nor coating.
After washing down the interior surface of the tank with a good quality water our painting subcontractor only check the salt soluble on the area that would be coated. They did not check the other area. Yes they did use high pressure pump during washing. But I am not sure the cleanliness on the top side. They did not use a scaffolding during washing.
The salt content on area that would be coated are within tolerance. So they assume it would be the same for other area. They don't want to build a scaffolding to check the area above 1 M.
Do you think this is acceptable ?
Your comments and advise is highly appreciated.





RE: Salt soluble test for un-coated surface
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RE: Salt soluble test for un-coated surface
Steve Jones
Corrosion Management Consultant
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RE: Salt soluble test for un-coated surface
Cloa, Do you mean the material of the tank ? It is carbon steel.
RE: Salt soluble test for un-coated surface
RE: Salt soluble test for un-coated surface
The water that we use for hydrotesting of this tank has more than 10000 ppm Cl. The exposure time (water filling to draining) about 3 weeks.
Yes we did wash the tank with clean and fresh water but we did not check the chemical content of this water.
After washing down, we check the salt soluble on bottom and 1 M shell and found an acceptable reading. But we did not check the shell area above 1 M.
The subcontractor said (I am still arguing) since bottom and 1 M shell is acceptable after washing so it would be the same for the rest of the shell.
My concern if there is a possibility that corrosion above 1 M on shell will effect to the coated area.