Fixer.nwg
Mechanical
- Jan 17, 2017
- 7
Hello.
Currently I´m working on a piping design that will transport highly corrosive fluid with low pH at 210 degrees Celsius. I have been trying to determine what kind of material will be suitable for such applications.
The velocity of the fluid can be assumed to be 48 m/s. From my research such harsh conditions will cause significant problems with Stainless steels where there is highly anticipated to be local corrosion which leads to fatigues and cracks.
Reports I have read has suggested that fiberglass materials has excellence in such conditions with low head loss. But has also been discussing that high temperature services might disable our opportunity to chose such a material, another obstacle is the fact I cannot find such a material group in ASME B31.3 which is the code I'm using for this design.
I have been looking into carbon steels and looked into the much used A53 and A106, however I can now assume they will have significant material loss each year due to corrosion and erosion which might cause the facility to fail before its required life span.
I have not studied materials in detail and are unfamiliar with estimating rate of corrosion/erosion. I was sure such rates was decided empirically, however a few reports of studies in the field I found online suggest that the rate of corrosion can be estimated by linear regression.
So now I'm not quite sure how to proceed with my problem, I have been thinking of regulating the pH to slow down corrosion and erosion, according to studies the erosion greatly increases with the lowering of the pH, some reports suggested 10 times more erosion by lowering the pH from 3 - 2. The problem with adjusting the pH are the cost as the flow of new fluid will be continuous.
How would an experienced piping engineer attack such a problem?
Regards.
Currently I´m working on a piping design that will transport highly corrosive fluid with low pH at 210 degrees Celsius. I have been trying to determine what kind of material will be suitable for such applications.
The velocity of the fluid can be assumed to be 48 m/s. From my research such harsh conditions will cause significant problems with Stainless steels where there is highly anticipated to be local corrosion which leads to fatigues and cracks.
Reports I have read has suggested that fiberglass materials has excellence in such conditions with low head loss. But has also been discussing that high temperature services might disable our opportunity to chose such a material, another obstacle is the fact I cannot find such a material group in ASME B31.3 which is the code I'm using for this design.
I have been looking into carbon steels and looked into the much used A53 and A106, however I can now assume they will have significant material loss each year due to corrosion and erosion which might cause the facility to fail before its required life span.
I have not studied materials in detail and are unfamiliar with estimating rate of corrosion/erosion. I was sure such rates was decided empirically, however a few reports of studies in the field I found online suggest that the rate of corrosion can be estimated by linear regression.
So now I'm not quite sure how to proceed with my problem, I have been thinking of regulating the pH to slow down corrosion and erosion, according to studies the erosion greatly increases with the lowering of the pH, some reports suggested 10 times more erosion by lowering the pH from 3 - 2. The problem with adjusting the pH are the cost as the flow of new fluid will be continuous.
How would an experienced piping engineer attack such a problem?
Regards.
