Cracking of welds posssibly
Cracking of welds posssibly
(OP)
We have SS tank ( 316 L ) that we think leaked where we welded it - the material going into the tank was at 200 F - could we have thermal shocked it - is this possible - is 200 F too hot - what do we do to prevent this in future? The tank is vertical hold capacity of 5700 gallons - leak is at bottom....





RE: Cracking of welds posssibly
What type of medium is the tank holding?
RE: Cracking of welds posssibly
RE: Cracking of welds posssibly
RE: Cracking of welds posssibly
Weld repairs involving pathches can be tricky and cracks at corner tie-ins have not been uncomon, especially with fillet welds. Proper weld sequencing is often required to prevent high induced weld strain at the corner tie-ins. Often these cracks are immediately evident through liquid penetrant testing but by no means always. Subsequent loading during operation will induce additional strain that can cause cracking.
How did you examine the completed patch-type weld repair? Vacuum box? Liquid penetrant?
RE: Cracking of welds posssibly
If the leak was observed within a few days of filling then the problem could be due to hot cracking of the weld deposit. If this is the case then the weld procedure has to be reevaluated. This can be determined via a replica of the surface.
If the leak occurred much later than stress corrosion cracking could be the problem. Much additional information is required. Analyses with out this additional information is irrresponsible and may lead to an unsatisfactory action.
RE: Cracking of welds posssibly
RE: Cracking of welds posssibly
underside? what is the tank resting on?
2. How were the cracks detected? someone ramed the tank?
what are the cracks characteristics (lenght,
location,orientation)
3. Patching cracks, this scares me; anyways was the
welding procedure qualified?
4. Please revisit the 200F when considering welding
SS.
5. I dont think your unorthodox repair had anything to
do with the leak; rather propagation of the cracks.
Regards,
RE: Cracking of welds posssibly
Most the times best solution is to replace the bottom.
Also watch your codes.