×
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

NFPA-11 galvanized pipe - inside or outside?

NFPA-11 galvanized pipe - inside or outside?

NFPA-11 galvanized pipe - inside or outside?

(OP)
NFPA-11 states 4.7.2.1* Galvanized pipe shall be used and 4.7.3.5* Galvanized fittings shall be used. For a tank farm (not a marine system), is the intent to require the use pipe that is galvanized on the inside? Can the pipe be field welded and touched up on the outside only?

RE: NFPA-11 galvanized pipe - inside or outside?

from the 2010 edition

4.7.2 Foam System Piping.

4.7.2.1* Galvanized pipe shall be used.

looks like they mean outside only:::


A.4.7.2.1 Corrosive atmospheres could require other coatings.


PLUS::::

4.7.2.2 Pipe carrying foam concentrate shall not be galvanized.



4.7.2.3 Piping in constant contact with foam concentrates shall be constructed of material compatible with and not affected by the concentrate.



4.7.2.4 Piping in constant contact with foam concentrate shall not have a detrimental effect on the foam concentrate.

not a welder but::
just says welding shall

4.7 Piping.

. 4.7.4.3* Welding shall conform to the requirements of AWS D10.9. 4

RE: NFPA-11 galvanized pipe - inside or outside?

(OP)
I agree, but then they go and give the friction factor for galvanized pipe, suggesting that they expect it to be galvanized inside. What do you think?

RE: NFPA-11 galvanized pipe - inside or outside?

Sorry that is as far as I go, not an engineer

Scott should give an answer sometime soon

RE: NFPA-11 galvanized pipe - inside or outside?

agree, but then they go and give the friction factor for galvanized pipe, suggesting that they expect it to be galvanized inside. What do you think?

do you have a section reference for above???

RE: NFPA-11 galvanized pipe - inside or outside?

(OP)
4.7.2.5 For the purpose of computing friction loss in foam
solution piping, the following C-values shall be used for the
Hazen–Williams formula:
(1) Galvanized steel pipe — 120
(2) Other C-values for corrosion-resistant piping materials in
accordance with NFPA 13

RE: NFPA-11 galvanized pipe - inside or outside?

Since the pipe must be submerged in hot zinc, galvanizing just the outside would be challenging (expensive). I would assume they mean the commonly available stuff that is galvanized inside and out.

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