Contact US

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!

*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

Recently, the gas process component

Recently, the gas process component

Recently, the gas process component

Recently, the gas process component has large change in some harmful component specially h2s which reaches to 1000 ppm.
Now we want to replace the existing bundle for gas air cooler by new one.
The existing material for the old bundle is
Tubes sa- 214
Tube sheets, plug plates and end platez sa- 516 gr.70
We will change only the material for tubes.
There is two options.
Using Sa-179 HIC Material
Using duplex stainless steel.
P : 1174 psi
T : 275 °F
FLUID Natural gas
In your opinion , what are the best material for tubes suitable for these conditions and keep no change in tubesheet material.

RE: Recently, the gas process component

A179 is edentical to yours anterior sa 214, meanwile A179 has HIC requirements according to nace, so is much better than the previous material. To chose a duplex material you have to think in bennefits versus costs, under certain condiction duplex ss can be an improuvment but in other condictions can be a worst choice you have to ponder your operating condictions and decide accordingly.


RE: Recently, the gas process component

I know that duplex s.steel will be better but Galvanic corrosion can occur where different metals are coupled in a conductive fluid. So i prefer using SA-179 but i have some doubts about its behaviour with wet H2S.

RE: Recently, the gas process component

Is your unit a standalone one, or are there others? Experience sharing could be useful.

Is this sudden increase in H2S a temporary phenomenon, or is it going to be a permanent feature?

Changing the air cooler metallurgy ONLY, and leaving the associated piping, reflux drum, etc. unchanged is not advised.

Using only two metallurgies for replacement is not advised too.

Kolkata, India

RE: Recently, the gas process component

How wet is it?
If you haven't seen corrosion (other than from H2S) then why go to a CRA.
Areyou sure that the rest of you steel piping will resist HIC/H2S?

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

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! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

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