corrosion rate calculation

• Mar 8, 2010

• #2

MJCronin

Mechanical

Apr 9, 2001

5,102

US

mecha...

It has been my expereince that corrosion rates for carbon steel piping are not really calculated.....they are estimated based on lab test results.

Lets say that in a certain service the corrosion rate from experimental data is 2 mills per year (.002 inches) if we want about a thirty year piping life, we would specify an additional "corrosion allowance" of .0625 inches on the pipe wall thickness.

Corrosion allowances used in piping design typically range from 0.0 to 0.125 inches in most service.

If the corrosion rate causes a piping lifetime that is too short, switch to a more corrosion resistant material.

-My opinions only

-MJC

 

Upvote 0 Downvote

• Mar 8, 2010

• #3

rneill

Mechanical

Jul 29, 2008

486

CA

Mecha20,

Please review the posting policies on Eng-Tips. It is contrary to the posting policies to cross post in multiple forums. Thanks,

http://www.eng-tips.com/viewthread.cfm?qid=266900&page=1

 

Upvote 0 Downvote

• Mar 9, 2010

• #4

Ron

Structural

Sep 24, 1999

16,336

US

Mecha20...corrosion rates are very specific to the use and environment of materials. As MJCronin noted, they are usually estimated from lab or field data.

Look at past performance of the material in similar applications and environment.

 

Upvote 0 Downvote

• Mar 16, 2010

• #5

texasmike45

Mechanical

Oct 6, 2004

15

US

Mecha20 Subtract your minimum thickness reading from the nominal thickness then divide by the amount of time in service. Will give you a general corrosion rate.

Mike

 

Upvote 0 Downvote