×
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

Design Concentration

Design Concentration

Design Concentration

(OP)
Hi Every one ,

On what basis do we select the design concentration for room to be protected with FM 200. Normally we used to take the design Concentration as 7% at 20 C .Please provide an answer on the basis of NFPA 2001.

RE: Design Concentration

(OP)
The Link which you provided does not work..No result is shown .No where does the link gives an answer to my question..

RE: Design Concentration

Sorry not a designer

But per 2001 looks like you need to decide what you are trying to protect and than use the manufacturer to design the system to,

And appears that is what the calculator does just need to plug in the numbers

Also can seek the help of a FPE

RE: Design Concentration

Some consideration needs to be given to the manufacturers approvals, however most system are based on a Class A or C hazard. In the US the MDC (Minimum Design Concentration) is based on the manufactures listing. During the Halon 1301 days, the MDC was specified in the standard. For countries following ISO standards, the MDC is specified in the ISO standard. NFPA 2001 requires the MDC to incorporates a 20% safety factor above the MEC (Minimum Extinguishing Concentration). It should be noted that those following the ISO standards use a MDC which has a 30% safety factor.

Most Manufacturers have the same design concentration for Class A and C hazards set at 6.25%. This assumes that the system will be automatically activated rather than manually activated. A Manually activated system is required to have a MDC which is 30% above the MEC. The logic follows that the system wouldn't be discharged until someone was somehow notified of the fire, at which time the fire would be considerably larger than what it would be if it were to discharge automatically.

Basing the MDC on 20°C is more dependent on what the end user intends the protected space to operate at, under "Ambient Conditions".

Class B hazards (engine rooms, etc.) require yet a higher design concentration based on testing that the manufacture has performed on the specific fuel.

Regards,
DM

"Real world Knowledge isn't dropped from a parachute in the sky but rather acquired in tiny increments from a variety of sources including panic and curiosity."

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