20201026-Fire Fighting -ENG.Iyad Al-Alem

STORAGE OCCUPANCIES DESIGN DENSITY:

Early Suppression Fast-Response (ESFR) Sprinklers for Palletized or Solid-Piled Storage of Class I Through Class IV Commodities ESFR sprinkler systems shall be designed such that the minimum operating pressure is not less than that indicated in Table 14.4.1 for commodity, storage height, and building height involved. The design area shall consist of the most hydraulically demanding area of 12 sprinklers, consisting of four sprinklers on each of three branch lines.

Early Suppression Fast-Response (ESFR) Sprinklers for Storage Commodities  Early Suppression Fast-Response (ESFR) Sprinkler. A type of fast- response sprinkler that has a thermal element with an RTI of 50 (meters-seconds)½ or less and is listed for its capability to provide fire suppression of specific high-challenge fire hazards.  ESFR sprinkler systems shall be designed such that the minimum operating pressure is not less than that indicated in Table 14.4.1 for commodity, storage height, and building height involved.  The design area shall consist of the most hydraulically demanding area of 12 sprinklers, consisting of four sprinklers on each of three branch lines.





EXAMPLE:

6 Fire Fighting systems IN RACK SPRINKLER HEADS SYSTEM

STANDARDS & REFERENCES  The most common standards used in this field is:  Jordanian fire Fighting Systems Code.  NFPA 13: Standard for the Installation of Sprinkler Systems.

Classification of Commodities.







In-Rack Sprinklers  System Size.  The area protected by a single system of sprinklers in racks shall not exceed 40,000 ft2 (3720 m2) of floor area occupied by the racks, including aisles, regardless of the number of levels of in-rack sprinklers.

Type of In-Rack Sprinklers.  Type of In-Rack Sprinklers.  Sprinklers in racks shall be ordinary-temperature standard-response or quick response  classification with a nominal K-factor of K-5.6 (80), K-8.0 (115), or K-11.2 (160), pendent or upright.  Sprinklers with intermediate- and high- temperature ratings shall be used near heat sources.  In-Rack Sprinkler Water Shields for Storage of Class I Through Class IV Commodities.  Water shields shall be provided directly above in- rack sprinklers, or listed intermediate level/rack storage sprinklers shall be used where there is more than one level, if not shielded by horizontal barriers.

In-Rack Sprinkler System Control Valves.  In-rack sprinklers and ceiling sprinklers selected for protection should be controlled by at least two separate indicating valves and drains.  In higher rack arrangements, consideration should be given to providing more than one in-rack control valve in order to limit the extent of any single impairment.

Maximum vertical distance between sprinklers at intermediate levels  The vertical distance from the floor to the lowest intermediate level and between levels shall not exceed 3,50 m or two tiers, whichever is the lesser,  An intermediate level shall be installed above the top level of storage except where all the roof or ceiling sprinklers are situated at less than 4 m above the top of the storage.

Horizontal position of sprinklers at intermediate levels  One row of sprinklers per level shall be installed for every 3,2 m of rack width. They shall be installed in the flue spaces wherever possible.





Location, Position, and Spacing of In-Rack Sprinklers.  Minimum Distance Between In- rack sprinklers shall be permitted to be placed less than 6 ft (1.8 m) on center.  Single rows of sprinklers shall be central above shelves. Double rows shall be positioned so that each row  is the same distance from the nearest shelf edge.

Water demand:  The maximum horizontal spacing between in-rack sprinklers shall be 10 ft(3.0 m).  The water demand for the in-rack sprinklers shall be based on a minimum flow of 30 gpm (114 L/min) discharging from the following number of sprinklers balanced to the ceiling sprinkler demand in accordance with 23.4.5:  (1) Six sprinklers where only one level of in-rack sprinklers is installed to protect Class I, Class II, or Class III commodity  (2) Eight sprinklers where only one level of in-rack sprinklers is installed to protect Class IV commodity  (3) Ten sprinklers (five on each of the top two levels) where more than one level of in-rack sprinklers is installed to protect Class I, Class II, or Class III commodity  (4) Fourteen sprinklers (seven on each of the top two levels) where more than one level of in-rack sprinklers is installed to protect Class IV commodity The required number of operating in-rack sprinklers must be balanced to the ceiling sprinklers,

7 Fire Fighting systems WATER SPRAY FIXED SYSTEMS FOR FIRE PROTECTION



STANDARDS & REFERENCES  The most common standards used in this field is:  Jordanian fire Fighting Systems Code.  NFPA 15: Standard for Water Spray Fixed Systems for Fire Protection.

 Exposure Fire. A fire that starts at a location that is remote from the area being protected and grows to expose that which is being protected.

DEFINITION  A water spray system is a special fixed pipe system connected to a reliable supply of fire protection water .  Equipped with water spray nozzles for specific water discharge and distribution over the surface or area to be protected.  The piping system is connected to a water supply through a deluge valve that can be actuated both automatically and manually to initiate the flow of water.  Automatic system actuation valves for spray systems can be actuated electrically by the operation of automatic detection equipment, such as heat detectors, relay circuits, and gas detectors, or mechanically by hydraulic or pneumatic systems, depending on the operating mode of the individual valves.

Exposure Fire. A fire that starts at a location that is remote from the area being protected and grows to expose that which is being protected. Exposure Fire. An exposure fire usually refers to a fire that starts outside a building, such as a wild lands fire or vehicle fire, and that, consequently, exposes the building to a fire.

DEFINITION  The deluge system application could be to extinguish fires, control burning, fire exposure protection (cooling) or prevention of fire.  The water spray is forcefully directed onto the object or surface being protected.  The pattern of spray nozzle discharge must carry water spray over the distance between the nozzle and the target, compensate for wind and draft conditions, and effectively hit the surface to be protected.  The required discharge density in gpm/ft2 10.2 (L/min/m2) and complete coverage of the area to be protected are also essential elements.  LPG tanks, flammable gas/liquid tanks and electrical hazards such as transformers, Oil switches, motors, cable trays/ Trenches, Service Tunnels, Transport Tunnels and other such hazards shall be provided with Deluge Water Spray System.

COMPONENTS  Fire pumps, controller, fire water tank, pipes, fittings, nitrogen/air supply, spray nozzles, isolation valves, deluge valve, pressure gauge, flow switch, test connection, drains, breeching inlet and signs.  All components of pneumatic, hydraulic, or electrical systems shall be compatible, listed and approved by Civil Defense.  System components shall be rated for the maximum working pressure to which they are exposed, but not less than 12.1bar (175psi).

COMPONENTS WATER SPRAY NOZZLES  Nozzles shall be open, listed and approved.  Selection of nozzles shall be based on discharge characteristics, hazard evaluation, ambient conditions, manufacturer’s instructions regarding positioning and coverage.

COMPONENTS DELUGE VALVE  The deluge System actuation valve shall be located as close to hazard protected as possible upon evaluation of hazard factors such as radiant heat flux, potential explosions, accessibility, discharge time and, drainage arrangement such as dikes, bund walls and trenches etc.

COMPONENTS: PIPING SUPPORT  The system piping shall be supported to maintain its integrity under fire conditions.  The piping shall be supported from steel or concrete structural members or pipe stands.  Pipe stands used to support piping shall be in accordance with following Table to determine maximum heights for pipe stands supporting various diameters of looped piping.

COMPONENTS: PIPING SUPPORT  The distance between stands shall be as per following Table .  Pipe stands shall be constructed of Schedule 40 threaded pipe, malleable iron flange base, and shall have a threaded cap top.  Pipe stands shall be anchored to a concrete pier or footing with either drop in anchors, quick bolts, or cast- in-place J hooks.  The piping shall be attached to the pipe stand with U-bolts or equivalent attachment.  The piping shall be supported and braced to restrict movement due to nozzle reaction and water surges so that system performance and integrity is maintained.

COMPONENTS DRAINAGE  All water spray system pipe and fittings shall be installed so that the system can be drained.  Drains shall discharge to a safe location, and drain valves, where provided, shall be accessible.  Drains shall not be directly interconnected with any sewer systems.

COMPONENTS: FIRE DETECTION AND ALARM SYSTEM  The selection, location, and spacing of automatic fire detectors for the actuation of fixed water spray systems shall comply with NFPA 72 Fire Detection and Alarm System.  The detection equipment requiring protection from the weather shall be provided with a canopy, hood, or other suitable protection.  Detectors shall be located so that no portion of the hazard being protected extends beyond the perimeter line of detectors.  When located out of doors or in the open, the spacing of fixed temperature or rate-of-rise detectors shall be reduced by at least 50 percent from the listed spacing under smooth ceilings.  Any flow from a single automatic nozzle of the smallest orifice size installed on the system or flow from any group of non-automatic nozzles shall result in an audible alarm on the premises within 90 seconds after flow begins.  Where a separate detection system is used to activate the water spray system, the alarm shall be actuated independently of the system water flow to indicate the operation of the detection system.  The flammable gas detectors and radiant energy sensing fire detectors shall be installed as per their listing specifications.

COMPONENTS: PILOT SPRINKLERS  Where pilot sprinklers are used for fire detection in indoor locations, the maximum horizontal spacing shall not exceed 3.7m.  Pilot sprinklers located outdoors, such as in open process structures, shall be spaced such that the elevation of a single level of pilot sprinklers and between additional levels of pilot sprinklers shall not exceed 5.2m.  The horizontal distance between pilot sprinklers installed outdoors shall not exceed 2.5m.  Pilot sprinklers shall be installed as per their listing specifications in special situations.

COMPONENTS:  REMOTE MANUAL ACTIVATION At least one manual actuation device independent of the manual actuation device at the system actuation valve shall be installed for all automatic systems installed in occupied areas.  BREECHING INLET Breeching inlet connections shall be provided for all water spray Systems.  GAUGES Pressure gauges shall be installed below and above the deluge valve, below the system actuation valve and on air or water supply to pilot lines.  STRAINERS Strainers shall be provided for all water spray systems so as to be accessible for cleaning and flushing.

DESIGN  The system and water supplies shall be designed to admit water into the piping and to discharge effective water spray from all open nozzles without delay.  Manual operation shall be permitted where automatic operation of the system presents a hazard to personnel and trained personnel are available to operate such manual systems.  Nozzle spacing (vertically or horizontally) shall not exceed 3m.  A single system shall not protect more than one fire area.  The hydraulically designed discharge rate for a single system or multiple systems designed to operate simultaneously shall not exceed the available water supply.

DESIGN  Extinguishment of fires by water spray shall be accomplished by one or a combination of the following methods: a. Surface cooling ) ‫( تبريد السطح‬ b. Smothering by produced steam c. Emulsification ) ‫( استحلاب‬ d. Dilution ) ‫( تخفيف التركيز‬ e. Other factors  Design Densities for various hazards, when demanded by other sections of this code or by Civil Defense hazard evaluation shall be as per following Tables.  The duration of Discharge shall not be less than 60 minutes.  All deluge water spray systems shall be hydraulically designed along with the manufacturer’s instructions.

DESIGN: Water Spray Design Densities and Criteria

Example Water Spray System for LPG gas Tank  Calculate the total area of the Tank a. Calculate the surface area of the Shell, A1= ������DL b. Calculate the area of the flat ends, A2= D2/4 c. Calculate the area of spherical (Concave or Convex) ends, A3= (D2/4+h2) d. Calculate the area of Hemispherical ends, A4= D2/2 e. Total Area of Tank, A = A1+A2+A3+A4

Example Water Spray System for LPG gas Tank  ii. Design Density Water Application Rate shall be d = 10.2 Lpm/M2 (2.7 Gpm/M2)  iii. Water Application Rate Required (Theoretical – Lpm) = A X d  iv. Establish minimum Pressure (Bar) required at remotest Nozzle. (As per manufacturer’s recommendations suitable to design density and area of application).  v. Establish minimum Discharge (lpm) through each Nozzle at the above stated pressure (Bar).  vi. Select number of Nozzles to be provided as per the coverage requirement.  vii. Find water required from each nozzle, = Q/No of nozzles  viii. Select appropriate Nozzle capacity i.e K-factor  ix. Adjust design as per calculated Flow and Pressure required at the tap off point.  x. Provide number of QBD Detectors as per the Coverage requirements.

Typical horizontal tank protection.

Typical Schematic for LPG Tank Water Spray System.

Typical Deluge Water Spray System Application for LPG Tank.

8 Fire Fighting systems DELUGE FOAM- WATER EXTINGUISHING SYSTEMS



STANDARDS & REFERENCES  The most common standards used in this field is:  Jordanian fire Fighting Systems Code.  NFPA 11: Standard for Low-, Medium-, and High-Expansion Foam.  NFPA 16: Standard for the Installation of Foam-Water Sprinkler and Foam-Water Spray Systems