×
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 fighting pump for hose reel systems

Fire fighting pump for hose reel systems

Fire fighting pump for hose reel systems

(OP)
hi,
The conditions are as follows:
-I just want to supply water for class I & III hose cabinets, there is not a sprinkler system.

-I calculate the required pressure by myself, only tell me the nominal flow capacity of the pump (gpm) and I guess a fire pump can supply up to 140% of its nominal capacity

-Condition: ordinary hazard group II

-Consider the pump is going to furnish 10 hose cabinets

I guess the required flow is 250 gpm, but I'm not sure, am I right?

Which pump do you recommend for this system?

RE: Fire fighting pump for hose reel systems

Look at nfpa 14

Your flow is wrong

RE: Fire fighting pump for hose reel systems

You are going to need a bigger pump.

Quote:

5-9.1.1* Minimum Flow Rate.

For Class I and Class III systems, the minimum flow rate for the hydraulically most remote standpipe shall be 500 gpm (1893 L/min). The minimum flow rate for additional standpipes shall be 250 gpm (946 L/min) per standpipe, with the total not to exceed 1250 gpm (4731 L/min). For combined systems, see 5-9.1.3.

Exception:  When the floor area exceeds 80,000 ft2 (7432 m2), the second most remote standpipe shall be designed to accommodate 500 gpm (1893 L/min).

You will need 1,250 gpm and lacking sprinklers 100 psi will be required at the top outlet.  Depending on the height of the standpipe you might not be able to use a 1,000 gpm pump if the building has any appreciable height.  It may be possible to use a 1,000 gpm pump in a four story building but, again depending on the curve it might, not work in an eight or ten story building.  In any event 1,000 gpm would be the smallest you could use.

You can also use any point on a pump curve out to 150%.
 

RE: Fire fighting pump for hose reel systems

(OP)
Thanks for your answers,
The reason I thought 250gpm is enough was because of Table 11.2.3.1.1 in NFPA 13-2002, which states the total combined inside and outside hose (gpm) for a ordinary hazard is 250.

So, installing sprinkler system usually reduces the total required flow?
What if the building is partially protected by sprinklers, how does the required flow change? For example, consider in a building only garages
are protected by sprinklers but the office areas are unsprinklered.
 

RE: Fire fighting pump for hose reel systems

A standpipe system is designed to nfpa 14.  Not nfpa 13

RE: Fire fighting pump for hose reel systems

Since this appears to be an open parking garage, have you considered applying Section 9.1.4 and avoiding the fire pump:

Where fire department pumpers cannot supply the required system demand through a fire department connection, an auxiliary water supply consisting of high-level water storage with additional pumping equipment or other means acceptable to the AHJ shall be provided.

 

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