Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


Estimating rate of corrosion

Estimating rate of corrosion

Estimating rate of corrosion


What is the basic steps of estimating rate of corrosion for piping runs?

Assuming uniform corrosion and erosion.

The fluid contains following in mg/kg:

CO2: 56,7
H2S: 85,3
SiO2: 694,8
Na: 152,2
SO4: 18,9

other parameters:
Temp: 210 degree Cecius
Velocity: 40m/s

Is there a way I can estimate the corrosion rate? i'm designing a pipe run that must have life span of 25years and preferebly I want to use Carbon steel. I am designing in accordance with ASME B31.3

RE: Estimating rate of corrosion

The issue is: will there be liquid water present? Normally, the CO2 corrosion rate would be assessed by corrosion predictive modelling


However, 210 deg C is beyond the validity range of most, if not all, models.

Steve Jones
Corrosion Management Consultant


All answers are personal opinions only and are in no way connected with any employer.

RE: Estimating rate of corrosion

Thank you for your quick response

RE: Estimating rate of corrosion

Silica at 48 metres per second will see off the pipe in double quick time. Erosional models are not quite as advanced as corrosion models, but modelling probably isn't really necessary in this case. Given the conditions, carbon steel on its own appears to be at the bottom of a short list of choices

Steve Jones
Corrosion Management Consultant


All answers are personal opinions only and are in no way connected with any employer.

RE: Estimating rate of corrosion

SJones Thank you very much for your specific informative answer.

Maybe you have some references or some materials to investigate. To me it seems like the temperature is won't let me chose a non metallic material.


RE: Estimating rate of corrosion

That is high velocity, very high.
Even without sny suspended solids plain carbon steel will have a short life.
Any elbows in this run?
I would guess that you are looking at 5-9-12% Cr grades for this service.
Even then 25 years may be optimistic.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: Estimating rate of corrosion

You did not mention if there is any moisture as asked by SJones. If there is then corrosion will be high. Once worked on a Project where there was Carbonic Acid in the pipees but the liquid also included high concentration of chlorides and the temperature was around 125 Deg C. No-one would give me a corrosion rate from the Client side . We could not use Stainless - Duplex was too costly so we had to go with Carbon Steel. I ended up taking 9mm for the corrosion allowance but could not guarantee the lifetime of the pipework.

RE: Estimating rate of corrosion

What is the fluid? Oil/water/sand? Gas/water/sand? Other? Erosion corrosion (even erosion alone) will highly limit life expectancy. Any chlorides? High temp negates use of rubber and other nonmetallic liners.

RE: Estimating rate of corrosion

I have discussed the high velocity and brought up that it will be a big problem and we came to a conclution that the nominal pipe size could be increased to lower the rate of erosion.

This is produced water, I was allowed to reduce the velocity by increasing the nominal pipe size. As DSB suggest the erosion would be to high with such a speed. I have reached a conclution that I will work with carbon steel.

It is just hard to estimate the corrosion/erosion allowance

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close