Corrosion Rate
Corrosion Rate
(OP)
Hello All,
I am conduction a vessel analysis in which I am no sure on something. Is there a formula/equation for the rate of corrosion (per year). My study is regarding a 53 year old tank in which I am trying to estimate a life expectancy before the material corrodes to the minimum required cylinder thickness. Thanks in advance!
-Richard
I am conduction a vessel analysis in which I am no sure on something. Is there a formula/equation for the rate of corrosion (per year). My study is regarding a 53 year old tank in which I am trying to estimate a life expectancy before the material corrodes to the minimum required cylinder thickness. Thanks in advance!
-Richard





RE: Corrosion Rate
If you have information as to the original wall thickness of the vessel and measure the current thickness you can use information to establish a linear corrosion rate for in-service conditions assuming constant conditions.
If you are asking what is the corrosion rate of a particular metal in a certain environment, this would require access to a corrosion handbook that lists material corrosion rate (mils/year) as a function of service temperature and environment.
Third, if you have access to API 579, this can guide you.
RE: Corrosion Rate
Short Term CR: previous thickness (prior inspection t) minus actual thickness (most recent thickness measurement) divided by time (years) between t previous and t actual.
Long Term CR: initial thickness (newly built vessel t) minus actual thickness divided by time (years) between t initial and t actual.
Remaining Life: t actual minus t required divided by corrosion rate.
RE: Corrosion Rate
I have the original nominal thickness, the current thickness readings (N,W,E,S, using lowest amount), and the age of the vessel. I basically used an equation, dividing the difference of thicknesses to the amount of years its been in service. Is this be correct?
RE: Corrosion Rate
RE: Corrosion Rate
Wow, 53 years and still in service. I wish I had held up that well.
rmw