PE Problem #9

6/13/2018

Inergen (IG-541) is being used for protection of several rooms which contain highly valuable historic documents. If the fire type is considered Class A and the design concentration of Inergen is provided, determine the clean agent-air mixture density.
a. 1.15 kg/cu. m
b. 1.25 kg/cu. m
c. 1.28 kg/cu. m
d. 1.44 kg/cu. m

Solution | Posted 06/14/18

10 Comments

FPE

6/13/2018 06:52:42 am

c. 1.28 kg/cu. m (SFPE 5th ed, Page 1526, Clean agent - air mixture density formula)

Rob

6/13/2018 09:43:14 am

c 1.27866

EdwH

6/13/2018 11:40:18 am

SFPE 5th
Table 44.17 IG-541 34.2 %
pg 1526 mixture density (kg/cu m) = 1.28 for Vd = 1.43

Ans == c.

David

6/13/2018 12:18:20 pm

1.28 kg/cu m

6/13/2018 02:18:26 pm

Orihara

6/13/2018 11:39:46 pm

Does the equation exist in SFPE 5th?

Orihara

6/13/2018 11:40:28 pm

I meant SFPE 4th.

jakes

6/14/2018 09:14:16 am

I don't have the 5th ed so I also use the 4th ed. Would really find it useful if reference was given to the 4th ed as well.

DIAA

6/15/2018 04:46:57 pm

D) 1.44 as per table A.5.4.2.2(b) class A min concentration for IG 541 is 34.2 then go to table A. 5.5.2 (f) at temp 21 with formula S=0.65799+0.00239 * 21.= 0.708 m3/kg which leads to denisty of 1.44 m3/kg

DIAA

6/15/2018 04:56:21 pm

I was not correct as I didnot proceed to extract the denisty of Mix with air it should be

1.44 kg/m3 x ( 34.2/100) + 1.202 kg/m3 x (100-34.2)/100= 1.28 kg/m3

Free Signup

Subscribe and learn something new each day:

Community

Thank You to Our Top April 2019 Contributors!

1. PETE
2. Mike
3. Dan W.
4. Dennis
5. RJ

6. Rusty S.
7. Dean M.
8. WES
9. Franck
10. Bruce S.

Your Post

The Toolkit

Sprinkler Designer or Engineer?

Get all of our tools, including the Sprinkler Database, Friction Loss Calculator, Fire Pump Analyzer and more:

FREE 30-DAY TRIAL

GET THE TOOLKIT

Filters

Exam Prep

2018 PE Prep Guide

Weekly Practice Exams

PE Problems

Visit July-October for daily Fire Protection PE Exam sample questions.

Solutions are posted the day after posting.

Comment with your solutions, questions or clarifications.

Please note that questions posted are unofficial and in accordance with NCEES rules are intended to be similar to actual exam questions, not actual exam questions themselves.

RSS Feed

Home - About - Blog - Contact - Exam Prep - Store

Copyright © 2019 MeyerFire, LLC
The views, opinions, and information found on this site represent solely the author shown and do not represent the opinions of any other party, nor does the presented material assume responsibility for its use. Fire protection and life safety systems constitute a critical component for public health and safety and you should consult with a licensed professional for proper design and code adherence. Some (not all) outbound links on this website, such as Amazon links, are affiliate-based where we receive a commission for orders placed elsewhere.