×
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

17-4 PH with Nitrous Oxide?

17-4 PH with Nitrous Oxide?

17-4 PH with Nitrous Oxide?

(OP)
Group:

I'd appreciate any opinions on use of 17-4 PH stainless for nitrous oxide service (pure NO, hospital application, 50 PSIG nominal).  

Pressure sensor manufacturer claims corrosion will be severe (wetted material is all 17-4 PH SS).  Gas supplier says it's fine.

If it's not fine, suggestions for a more compatible material?

Many thanks and good on y'all,

Goober Dave

RE: 17-4 PH with Nitrous Oxide?

We are running 17/4 PH SS as compressor wheel for compressing NOX. The concentration of N2O varies from about 50%, normal, to 90%. The inlet gas is saturated with H2O with temperatures form 35C to 120C. There has not been any corrosion in over 15 years service. On stream time is about 80%.
This is the only area where we use 17/4 in contact with NOX. Our material of construction is normally 304ELC or Titanium.
I don't know if the company that converts NOX to N2O uses any 17/4 wetted parts in their process.  

This compressor actually compresses the off gas from our process for recycling or send it to a guest company that converts the NOX to N2O Oxide for the trades, whipped cream chargers and especially medical use.
 

RE: 17-4 PH with Nitrous Oxide?

(OP)
Say, that's great testimony, Uncle Syd!

Thanks for responding.

Good on ya,

Goober Dave

RE: 17-4 PH with Nitrous Oxide?

Just checked on the 17/4 wheel and it's still in use and has been inspected 3 times and no problems found. The service has changed slightly in the last couple of years as it only sees NOX for 50% of the time while compressing air the remainder.

I also verified that the 17/4 wheel replaced the original Ti 6AL-4V wheel that underwent severe corrosion in this service. The Ti mentioned in my first post is Ti Gr2.   

RE: 17-4 PH with Nitrous Oxide?

(OP)
Thank you again, Uncle Syd.

We electrical power and controls engineers don't get the education we need in materials...  Corrosive behavior, in particular, is hard to quantify.

Best to you,

Goober Dave

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