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


Dear all engineers, I have a pro

Dear all engineers, I have a pro

Dear all engineers, I have a pro

Dear all engineers,

I have a project where the corrosion allowance is not stated by client or any standard. Basically I need to use the carbon steel pipe to transfer the thermal oil inside a heat exchanger. The temperature can go as high as 410 degC and the pressure at 20 barg. May I know if that any way I can specify the corrosion allowance for this case so that I can calculate the minimum required thickness? Thanks!

RE: Dear all engineers, I have a pro

What corrosion rate are you expecting for carbon steel when exposed to the thermal oil?

Steve Jones
Corrosion Management Consultant


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

RE: Dear all engineers, I have a pro

If the oil is clean then the corrosion rate will be zero, and you won't need any corrosion allowance.

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

RE: Dear all engineers, I have a pro

Hi, I am not sure about the corrosion rate that I should set, but I can say that the thermal oil I am trying to use is Therminol synthetic heating fluid. And the design life of the piping is about 22 years. Maybe they will help us to indicate what kind of corrosion allowance I should apply in my thickness calculation?

RE: Dear all engineers, I have a pro

Generally the minimum Corrosion Allowance depends on the Project Specification.
For CS Piping even the Fluid is water one has to take a certain minimum value.


Hard Work with Smartness is the key to success

RE: Dear all engineers, I have a pro

Standard practice is to use 1.0mm CA for nominally non corrosive service. But you have to keep an eye on this Therminol fluid for pH during plant operation, and also design for and keep a N2 blanket on the expansion drum, else corrosion rates will be higher.

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