6 replies to this topic

[farid.k]

hye guys,

 

one short question. currently we plan to install 2 firewater pumps (1 running 1 standby). however both is electrical motor driven pump. I just question whey they don't put at least 1 motor 1 diesel driven. try to check with nfpa 20 but no statement whereby must have 1 diesel and 1 motor. your response is highly appreciated.

[Art Montemayor]

As far as my experience is concerned - I made a critical total assessment of an existing, large firewater pump installation at a major LNG plant last year - you may not be legally allowed to use electric motor drives on your firewater pumps.  You should double-check with your local Fire Marshall and your Insurance carrier.

 

The reason for employing diesel engines and not electric motors is quite simple:  in a fire case, the electric substation or the power lines could be affected either before or during a major fire within your facility and the consequences would be not only embarrassing, but also fatal.  Unless you can prove that there is no way that the electric power can be affected by a local fire, I would never rely on electric motors to deliver all the required fire water during a fire case.

[breizh]

Hi ,
You need definitely to have both electrical and diesel engine . At first you may have only diesel engine , this in case of power outage . This was acknowledged by Insurance company .

Breizh

Edited by breizh, 15 October 2014 - 01:31 AM.

[ankur2061]

Farid k,

 

The majority of the installations to my knowledge have one firewater pump with an electric motor and the second with a diesel engine. However, there have been a few instances where both the pumps were either electric motor driven or diesel engine driven. As explained by Art Montemayor, local laws (country / state) or company laws governing the firewater system design and configuration will determine the driver selection of the firewater pumps.

 

If there are no clear guidelines, one diesel engine and one electric motor driven pump is recommended.

 

Regards,

Ankur.

[farid.k]

Thanks all.I do appreaciate for your comment.

[farid.k]

They have big electric generator to provide power supply in case of power failure. I thing this reason would be sufficient for not using diesel driven.

[Brocklesnar]

But then, for both electric motor driven fire pumps, you should ensure the electric feeds are from two separate power supply sources.

For ex: supply to 1st electric pump can be part of plant auxiliary bus, and supply for 2nd electric pump should be from a feed from separate electric grid which is expected to be live if plant auxiliaries power fail.