Smart questions
Smart answers
Smart people
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Member Login




Remember Me
Forgot Password?
Join Us!

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips now!
  • 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!

Join Eng-Tips
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Donate Today!

Do you enjoy these
technical forums?
Donate Today! Click Here

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.
Jobs from Indeed

Link To This Forum!

Partner Button
Add Stickiness To Your Site By Linking To This Professionally Managed Technical Forum.
Just copy and paste the
code below into your site.

HeshamM (Mechanical) (OP)
18 Dec 06 7:25
To calculate the flow rate of the jockey pump, it is related to one sprinkler flow rate and the leaking rates as per the figures in the NFPA (at design stage it is not possible to get that actual), would 10% considered a correct value or is it too much?
TravisMack (Mechanical)
18 Dec 06 8:17
HeshamM:

I don't know that it is an exact science, but the main supplier I have used sizes the jockey pump to be about 1% of fire pump rating.  
stookeyfpe (Specifier/Regulator)
18 Dec 06 9:20
Hesham

I don't know if I would consider the flow rate of one sprinkler to serve as the basis for the design of a jockey pump. Once a single sprinkler operates, depending on its location and required discharge pressure, the fire pump may be required to satisfy the hydraulic demand. If the building is used as a office, this method would be reasonable. If it is a warehouse protected by ESFR sprinklers I would state that the design is not reasonable.

Remember that a jockey pump is a pressure maintenance pump. Your system remains hydrostatic until a) a sprinkler operates or b) you have a leak upstream of the pump discharge.

I would defer to Travis's wisdom and ensure that the pump has a flow rate of 1% of the pump rating and has the appropriate pressure rating for your system.
SprinklerDesigner2 (Mechanical)
18 Dec 06 9:32
The smaller the better.

I always hated those Model J pumps with the 5 HP motors and two second on/off cycle that would give a bang of water hammer.

1% sounds good.
HeshamM (Mechanical) (OP)
19 Dec 06 6:05
If I have a 1000 GPM @ 14 bar Main Fire pump, does 10 GPM at such high pressure sounds O.K.?
I feel it is too little
TravisMack (Mechanical)
19 Dec 06 8:03
I would be comfortable with a 10-15 gpm pump.  The jockey pump should only maintain system pressure and be able to handle "small" leaks.  The jockey pump is not intended to handle fire sprinkler discharge.  If you have a leakage rate greater than 15 gpm, then you have bigger issues than the size of the jockey pump.
SprinklerDesigner2 (Mechanical)
19 Dec 06 10:00
I couldn't agree more with TravisMack if a 10 gpm jockey pump can't keep up then your issues are a lot bigger then the jockey pump.

10 - 15 gpm is an excellent size IMO.

MJCronin (Mechanical)
9 Jan 07 10:27
To all...

What does the NFPA standard say about jockey pump sizing ?

_MJC

  

TravisMack (Mechanical)
9 Jan 07 14:29
2-19* Pressure Maintenance (Jockey or Make-Up) Pumps.
2-19.1
Pressure maintenance pumps shall have rated capacities not less than any normal leakage rate. The pumps shall have discharge pressure sufficient to maintain the desired fire protection system pressure.

A-2-19
Pressure maintenance (jockey or make-up) pumps should be used where it is desirable to maintain a uniform or relatively high pressure on the fire protection system. A jockey pump should be sized to make up the allowable leakage rate within 10 minutes or 1 gpm (3.8 L/min), whichever is larger.

That is exactly what it says about jockey pumps smile

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!

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close