Oxygen in dehexanizer

[corrjay]

Reports from a plant are they are having corrosion problems in their dehexanizer. It was found that there was oxygen present in the system. Other than any trucked in fluids or leaking flanges are there any other sources of oxygen in this system and/or what are the best methods to troubleshoot the pipeline failures.

 

[sshep]

Corrjay,

This is a major question for which you have supplied no process or failure data. Without process description or data, you are unlikely to get much help in finding the underlying problem.

With respect to oxygen sources, what about water? Cooling water or steam leaks into the process can lead to corrosion issues. Following the water trail can often lead to effective corrosion mitigation.

The best start to finding the source of corrosion is to cut out the failed section for metallurgical analysis. Is this pitting, general thinning, crevices, deposits, heat affected zones, etc? If you know nothing about the failures then the chance of finding the cause is very low. Let an expert take his microscope to the problem and do some elemental analysis of the corrosion products.

good luck,
sshep

 

[dcasto]

What kind of plant has a dehexanizer (sounds like a 1960 LO plant to me).

How do you know you have O2, could the O2 only be in the sample. O2 by it's self won't corrode, wheres the water coming from.

Let it all out....