×
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

Spiral Pipe Maximum Vacuum

Spiral Pipe Maximum Vacuum

Spiral Pipe Maximum Vacuum

(OP)
I am looking for imformation on the maximum allowable vaccum on a 24 inch diameter 22 gauge stainless steel spiral pipe.  SMACNA only gives lengths up for pressures up to 10".  I am looking to calculate higher vacuum pressures.

RE: Spiral Pipe Maximum Vacuum

mrkhubert,

Contact a manufacturer of stainless steel spiral duct, like Lindab (www.lindab.com).  They can tell you.

---KenRad

RE: Spiral Pipe Maximum Vacuum

It addition to SMACNA's "HVAC Duct Construction Standards-Metal & Flexible", they also publish "Round Industrial Duct Construction Standards".  This second publication takes you up to -30" wg.  Trouble is it doesn't include the spiral duct types which can presumably handle more pressure.

At any rate, one thing that has to be established first is the material handling class of the duct.  This is comprised of 4 classifications ranging from non-abrasive applications to highly abrasive.  Per United McGill's literature (and this seems in agreement with SMACNA's lit.), you need 20 ga min. for 24" spiral duct up to -10"; 18 ga. for -10 to -20", etc. for just the least severe classification.  There are other iterations depending on the level and type of additional reinforcing, so it's not like there is one exact answer.

Unstiffened, you shouldn't really go past -2" wg for a 24" diam spiral seam duct (this is shown in the "HVAC Duct Construction Standards-Metal & Flexible"--presumably the one you already have).  

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