×
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

fire sprinkler return bend

fire sprinkler return bend

fire sprinkler return bend

(OP)
1. nfpa 13 does not seem to say anything on the length a drop can be after the return bend

just wonder if any thoughts about that.

this is on a pre action system


any thing in the code about having to drain each drop after a trip??


any other thoughts about return bends???



 

RE: fire sprinkler return bend

No length limit.

Must be installed in non-freeze environment.

Single sprinkler does not have to be drained.

RE: fire sprinkler return bend

I agree with SprinklerDesigner2 however if you consider yourself a top designer I suggest keeping the branch as low as possible to allow proper drainage. Is not required but it says a lot about your design experience. This way less water will remain in the drop.
This is just a constructive opinion.  

RE: fire sprinkler return bend

I've always viewed goosenecks as a design compromise at best.
 Isn't the shape of the return bend supposed to function as air trap and thus keep the drop from filling with water in most cases?
 I try to avoid using them wherever possible.

Alex Traw
Rainbow Fire Sprinklers
Albany, Oregon
 

RE: fire sprinkler return bend

I ma not sure about that RaimbowFS. In my 17 years of experience I allways found water in the drop however as I said before if branch is kept as low as the RC it will drain properly.

RE: fire sprinkler return bend

All drops have water in them, the size of a drop on a pre-action system, by prudent design should be as short as possible, this is best accomplished by the length of the riser nipple off the line or main being as short as possible, if pitched then varied in length, which is not actually required in a heated space, pitching that is.

spkreng, CET

RE: fire sprinkler return bend

I should have phrased my comment better, because I do realize that  the drops always get water in them. I meant to say that the theory of goosenecks is to keep water out of them by trapping that little pocket of air. That's what I learned way back when, anyway.  

Alex Traw
Rainbow Fire Sprinklers
Albany, Oregon
 

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