Cooling coil corrosion in 316L reactor
Cooling coil corrosion in 316L reactor
(OP)
We have several reactors made of 316L SS. One of our new reactors is exhibiting significant corrosion on the cooling coils inside the reactor, which is not evident on the rest of the reactor or any of the other reactors. There aren't any products that are unique to this reactor. The manufacturer of the vessel has been less than candid with us about other design flaws with this vessel and we are inclined to believe that the cooling coil wasn't made with 316L as was specified. Is there any way to determine the type of SS the coil is made of in situ, or will we have to remove part of it to be analyzed elsewhere? Is there any reason we might see corrosion on the cooling coil and not the rest of the reactor? Has anyone encountered a similar problem? Any help would be appreciated.
Thanks
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RE: Cooling coil corrosion in 316L reactor
It seems as if the cooling coil should be replaced anyway, so make sure the cooling coil has the proper ASTM marking on it and that the fabricator provides material certifications. You may want to inspect the fabricated coil prior to shippment to confirm that everything meets specifications.
Insure that the cooling coil is not failing from some other mechanism, such as Stress Corrosion Cracking (SCC) that may be caused by the stress cycles contributed by chemicals in the reactor. Stainless Steel is susceptible to SCC under certain conditions, even if the supplier provided 316L on the coils. Under these conditons the vessels can be fine and you can see failure of the coils. A metallurgical lab can look at the microstructure and determine if SCC is a mechanism of failure. If it is then the new coil can still be supplied in 316L but must have lower stress values for a longer service life.
Good Luck
RE: Cooling coil corrosion in 316L reactor
There are test kits available to know whether a steel is of 316 grade or not. (Which shows you Mo content) But not for 316L which indicates low carbon content. You have to go for chemical analysis test.
If the welding rods used or not proper there may be problems of corrosion. (check where the corrosion is starting from)
Regards,
Truth: Even the hardest of the problems will have atleast one simple solution. Mine may not be one.
RE: Cooling coil corrosion in 316L reactor
RE: Cooling coil corrosion in 316L reactor
RE: Cooling coil corrosion in 316L reactor
RE: Cooling coil corrosion in 316L reactor