7/29/2019 FM-072M-0-224

1/4

Integrated Compressed Air FoamSystems for Fixed Piping Networks

ICAF Case Study Series:

Protection of Diesel Generators &Machinery Spaces

Doc. FM-072M-0-224 A May 2006

7/29/2019 FM-072M-0-224

2/4

Case Study Series Diesel Generators & Machinery Spaces

ICAF Compressed Air Foam Systems

FM-072M-0-224 A

Overview

Stationary diesel engines are often used coupled withgenerators for primary or emergency power

generation. They are also used to drive pumps andcompressors in the petrochemical and gas-pipelineindustries and with co-generation gas turbineinstallations.

The investment directly associated with these enginesis fairly high but that is often only a fraction of the valuefor the service they provide. Loosing them to firedamage often has dramatic consequences for the userand ultimately leads to business downtime which cannever be afforded. The cost of this downtime can becatastrophic to a company or to a small communitywhen for example, the generator provides power to anentire village as is often the case in remote areas.

Diesel engines come in various sizes andconfigurations and the main hazard is associated withcombustible or flammable liquids. The fire hazard ismainly centered around the fuel and lubricationsystems and include:

- Ignition of the fuel in case of leaks on hot surfaces,

- Lubricants, hydraulic fluids and sometimes, even thefluid being pumped or compressed,

- Ignition of flammable vapors or combustibles instorage close to the diesel engine,

- Pool fire from the fuel or lubricant leaking from abreak in the equipment.

Diesel engines will produce temperatures easilyreaching 1000

oF (538

oC) near manifolds, exhausts and

mufflers that can easily ignite any combustible comingin contact with them, such as building penetrations,and require special precautions.

Problems with the use oftraditional technologies

Typically, diesel engine installations are protectedusing traditional fire sprinklers. In the case of remotelocations, water supply quickly becomes an issuepreventing their use.

They are also frequently protected by fixed CarbonDioxide systems (CO2) but with the recent casualtyrates from accidental discharges on the increase andnew environmental concerns about gases thatcontribute to the green house effect, they are rapidlyloosing popularity with users.

Similarly, diesel engines are sometimes protected bydry chemical systems but the risk of corrosion to the

equipment by the extinguishing agent is often aproblem, specially in the case of unattendedinstallation.

Other installations are sometimes protected with cleanagent systems but some of them will decompose oncontact with the engine hot surfaces, producing highlycorrosive or toxic chemicals, damaging for theequipment and / or people in the premises.

Typical to gaseous systems in general, the enclosureintegrity should also be maintained at all times and thisis often a problem in actual working conditions,severely limiting the ability of extinguishing gases toextinguish the fire.

Design with ICAF

In this example, protection is required for a dieselengine room containing three generators side by side.In this case, the room is simply flooded withCompressed Air Foam (CAF) from nozzles installed atthe ceiling as shown on Figure 1 below.

NFPA-11, TIA #05-1 in art. 7.15 states that where fixedspray type systems are used to protect roomenclosures, the minimum density shall be no less than0.04 gpm/square foot (1.63 l/min/square meter)Furthermore, system discharge duration shall bedesigned for a minimum period of 10 minutes fordeluge-type systems (art. 7.16).

The quantity of foam concentrate is reduced by usingthe ICAF Systems since its high efficiency is achievedwhile using only a 2% concentration of AFFF foamconcentrate instead of the usual 3% !

Using FireFlex Systems FM Approved ICAF DesignManual, the designer will locate a grid of total floodingnozzles to cover the generator room area.

The designer has to take site conditions inconsideration before deciding which design will bestprotect the hazard. In some cases, additional nozzlesmay need to be installed directly at the generators andcareful evaluation of the various hazards should bemade to determine if they are required.

7/29/2019 FM-072M-0-224

3/4

Case Study Series Diesel Generators & Machinery Spaces

ICAF Compressed Air Foam Systems

FM-072M-0-216 A

Project Scope of Work

This simple installation will provide foam coverage onthe surfaces of the generators themselves but also on

the floor around them, thus providing protection in caseof fuel leaks. Figure 1 below shows a typical ICAFSystem installation with its grid of discharge nozzlesinstalled at the ceiling level.

The balanced flow piping is simple to install and ofsmaller diameter than the equivalent foam-watersystem, reducing the costs for the installing contractor.

Figure 1 ICAF Nozzles layout:

The ICAF system required for protecting this hazardincludes a 10 gal. tank of foam concentrate with two (2)

compressed air cylinders, representing a small footprint (see Fig. 2 below).

The ICAF system requires so little water that even ifthe local water supply was inexistent, as is often thecase in remote locations, the problem could be easilyresolved by installing a water reservoir of 500 gal.capacity that is pressurized on system activation. Thesystem would then be completely stand-alone and thiscritical installation would be adequately protected.

Figure 2 ICAF System footprint:

Foam TankCompressed Air

Cylinders

ICAF System Controls

Conclusions

Fire protection designers now have an additionaweapon in their arsenal of fire combat tools. The ICAFtechnology is emerging as an environmentally friendlysolution for protection of diesel generators, machineryrooms and other similar hazards.

With ICAF Systems installed on their premises, planowners can now better protect their investment whileachieving total fire suppression in case of accidenta

fires.Should you have questions regarding this applicationor any other involving flammable liquid hazardscontact FireFlex Systems Inc. Our engineers will workthe project with you and find the best layout for youspecific application.

7/29/2019 FM-072M-0-224

4/4

Case Study Series Diesel Generators & Machinery Spaces

ICAF Compressed Air Foam Systems

FM-072M-0-224 A

FireFlex Systems Inc.1935 Lionel-Bertrand Blvd.

Boisbriand, QC, Canada J7H 1N8T: 450-437-3473 Toll free: (866) 347-3353

Fax: (450) 437-1930

For additional information about ICAF Systems, pleasevisit our web site at: http://www.fireflex.com