×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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

Jobs

Best material for alkaline & acidic services?

Best material for alkaline & acidic services?

Best material for alkaline & acidic services?

(OP)
We have a neutralisation basin which supplies fresh caustic (20% conc.) to gas scrubber & the return line comes to basin. Now within one year the return pipeline failed 3 times at different locations near to basin & the failure was not on the joints but in pipe itself. Failure is in form of pinhole in pipeline. The process study shows the pH value for the return service is 4 (which is acidic). The whole pipeline is A53 GrB designed for 20 % NaOH @ 0 degC.

Kindly suggest any solution?

RE: Best material for alkaline & acidic services?

sounds like a job for a non-metallic.
whoever selected steel in the first place should be paying for all of this.  It had zero chance of survival.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: Best material for alkaline & acidic services?

Could HDPE do it. It is good to acid and alkali so long as there are not also strong oxidizing agents present. Even then it seems to work although it may be with reduced life.

Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules
 

RE: Best material for alkaline & acidic services?

Agree with Ed....composite or plastic (many formulations available...) would be correct.

RE: Best material for alkaline & acidic services?

(OP)
There is one correction for the design temp. It should be 70 degC.

What bout FRP?

RE: Best material for alkaline & acidic services?

Should be OK but it depends on the resin. Strong hot caustic gets into polyesters and eats them away. I don't about caustic and epoxy. Strong hot caustic can also get into some glass.

I still say HDPE or PP, depending on physical load and support.

Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules
 

RE: Best material for alkaline & acidic services?

I was thinking fibergalss with selected resin inner layer.  This would allow you to select the liner resin separate from the strength member.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

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!


Resources