×
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

New Sprinkler drops in existing System: Please read

New Sprinkler drops in existing System: Please read

New Sprinkler drops in existing System: Please read

(OP)
My building just recently went through a fire inspection in which some some sprinkler heads are run off 1/2" pipe. I must replace this with 1" pipe and then use a 1" x 1/2" reducer for the sprinkler head. However the inspector tells me that I must replace the 1" x 1" x 1/2" Tee with a 1" x 1" x 1" Tee so that the sprinkler pipe is no longer on 1/2" pipe. The sprinkler system is existing and for me to replace the Tees would mean that I would have to remove the piping to get at the Tee for replacement. What can I do to replace the Tees? Is there a pipe fitting where I can tap into the existing pipe and run my sprinkler drops from there? Pipe sizes run from 6" to 1".



RE: New Sprinkler drops in existing System: Please read

Yes...you will have to replace all of the 1/2" pipe.  You can change out the end elbow on the line which is probably 1"x1/2" elbow to a 1" elbow.  For all of the other heads, you can purchase a __x1" mechanical tee to make the drop in 1" pipe.  Then, just plug all of the 1/2" outlets.  This will prevent you from being required to replace all of the piping.

Travis Mack

RE: New Sprinkler drops in existing System: Please read

Actually, if you are not in an earthquake zone and you are piping to a new ceiling, NFPA 13(2002 edition) section 8.14.19.3 on Revamping of Pipe Schedule Systems allows you to install 4" long nipples the same size as the outlet and then you increase to a minimum 1" size.


That being said I do not believe it is a very good practice and I do not allow it on my projects.  Read the appendix material in NFPA 13 for additional clarification of the intent of this section of NFPA 13.

RE: New Sprinkler drops in existing System: Please read

(OP)
I kind of figured that a mechanical Tee would do the trick and I started pricing them. However so far I cannot find one for pipe size less than 2". What is the manufacturer of such a tee? Alot of the piping is 1 1/2" where I need to do the sprinkler drops. I was a little slack on the details as to where the heads are going. What I have is a hallway with a suspended t-bar ceiling. The wall on either side of the hallway are 1 hour fire rated. The old ceiling above according to the inspector is 30 minutes. The existing sprinkler pipes are above the t-bar ceiling and under the old one. The old heads were in upright position and 1/2" pipe used to bring the heads into the newer t-bar ceiling. When I removed the tiles we discovered this. He wants it fixed. Who ever done this did it wrong. Using a 4" nipple and then using 1" pipe sounds great. But I would have to connect the old configuration which is upright to the new using 1/2" elbows into a pendant position. Could I use 4" nipple in upright from the existing tee, use a 1/2" x 1" reducing elbow, run 1" pipe horizontally to where I need, and then make the drop with a 1" x 1" elbow, 1" pipe and then the pendant on a 1" x 1/2" reducer. Thank you for your replies.

RE: New Sprinkler drops in existing System: Please read

It sounds like you are describing the diagram shown in NFPA 13(2002 edition) section 8.14.19.3 as previously referenced.  I recommend you look at that diagram and read the section to verify it is applicable to you.

As for mechanical tees on smaller pipe sizes the smallest I am aware of is 1-1/4".  This is a victaulic snap-let product.  Check out the following link:

http://cf.victaulic.com/products/pdf/11....

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