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.


stagnate boiler feed water with 321 stainless steel

stagnate boiler feed water with 321 stainless steel

We have 321 stainless steel radiation tubes of furnace that filled with stagnate boiler feed water (doesn't contain chloride)during the maintenance and welding work due to safety precautions. Can this water have harmful effect on this material under such conditions and period of time?

RE: stagnate boiler feed water with 321 stainless steel

is your BFW well treated (inhibitor, oxygen scavenger)
what is the O2 content ?
I would say that well treated BFW, even stagnant, is not corrosive to SS 321.


RE: stagnate boiler feed water with 321 stainless steel

If the stagnant boiler feedwater contains oxygen it will result in corrosion pits to the 321 stainless steel tubing. There should be no feedwater touching these tubes, if possible.

RE: stagnate boiler feed water with 321 stainless steel

My preference is definitely to keep austenitic heater tubes under dry, O2 free nitrogen purge if at all possible.

Be careful, depending on what the furnace has run, polythionic acid stress corrosion cracking could be a concern, even on 321 tubes (impossible to know that you haven't had a hot spot that's hot enough to sensitize the tubes). Not just on the ID either, if there's sulfur in your fuel gas, you can get OD initiating PASCC. If you're dead set on filling them with water and there's any sort of sulfur in whatever is being heated in the tubes, you'll probably want to use a soda ash solution rather than straight boiler feed water.

Nathan Brink

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