20200112-Firefighting Systems Design By Elite Software- Eng. Iyad Alalem

7. Floor /Zone Control Valve Assembly  The water flow switch shall be mounted on top of the pipe or as recommended by the original equipment manufactures data sheet.  All the equipments of ZCV assembly shall be rated for the system working pressure and water temperature service and approved by the Civil Defense department.  The ZCV assembly shall be installed in an easily accessible & visible locations, preferably inside the star enclosure above the required headroom height.  ZCV assembly shall be provided with an identification sign board in a visible location in both Arabic & English languages.  Where ZCV assembly is located in a closed room or shaft, access door or panel shall be provided with an identification sign board in visible location in both Arabic & English languages.  ZCV assembly shall be installed such that it has adequate clearance space around it for testing and maintenance purposes.

8.Pressure reducing valve (PRV):  Pressure reducing valve station shall consist of:  by-pass arrangement having all equipments & accessories same as in the main connection as shown below.  The rated working pressure of all devices including pressure reducing valve installed on upstream side of PRV shall be higher than the inlet pressure of PRV station.

8.Pressure reducing valve (PRV):  In portions of systems where all components are not listed for pressure greater than 12.1 bar , a listed pressure-reducing valve shall be installed .  Pressure gauges shall be installed on the inlet and outlet sides of each pressure-reducing valve.  A relief valve of not less than 13 mm in size shall be provided on the discharge side of the pressure-reducing valve set to operate at a pressure not exceeding 12.1 bar.  A listed indicating valve shall be provided on the inlet side of each pressure-reducing valve, unless the pressure-reducing valve meets the listing requirements for use as an indicating valve.  Means shall be provided downstream of all pressure-reducing valves for flow tests at sprinkler system demand.

9. Support of Sprinkler Piping  Sprinkler system pipe installations shall be adequately supported as per the good engineering practice in accordance with internationally accepted standards.  All the supports provided for sprinkler system piping shall allow free movement for expansion or contraction of pipe work .  Sprinkler system main risers shall be supported by riser clamps or by hangers located on the horizontal connections within 600 mm of the center line of the riser. Riser clamps supporting risers by means of set screws and Riser clamps anchored to walls using hanger rods in the horizontal position shall not be permitted to vertically support risers.  Vertical risers supported at the bottom of riser at lowest level, at each level, above & below the offsets and top of the risers. The maximum distance between each riser support shall not exceed 3 m.

9. Support of Sprinkler Piping  Anchor support shall be provided at the base (bottom) of each vertical riser pipes to withstand the total weight of pipe with water and to prevent the movement by an upward thrust in the sprinkler system.  Horizontal runs of sprinkler pipes shall be supported in such that each support shall be designed to withstand the load 5 times the weight of water filled pipe, plus 115 kg.  However the hangars spacing and hangar rod size which supports horizontal pipes shall be not less than the distance specified in Table below:

Support of Sprinkler Piping Types: END PIPE SUPPORT SEISMIC PIPE SUPPORT RISER CLAMPS WALL AND ROOF PIPE SUPPORT ANCHOR SUPPORT

10. Drains :  The complete sprinkler system piping shall be designed and installed in such a way that the entire water can be drained.  A main drain valve shall be installed on each sprinkler system main riser on down stream side of an Alarm Check valve.  The size of main drain valve (alarm check valve) shall not be less than 50mm dia. Auxiliary drains shall be provided where a change in piping direction prevents drainage of system piping through the main drain valve.  A listed and approved combined test & drain valve is permitted to use in sectional or floor zone control valve assembly.  A drain riser shall be installed beside the sprinkler system riser pipe.  The main sprinkler riser drain should discharge to an open drain outside the building at a point free from the possibility of causing water damage  The main sprinkler riser drain should discharge to an open drain outside the building at a point free from the possibility of causing water damage .

11. Flushing Connections:  Provision for Flushing Systems.  All sprinkler systems shall be arranged for flushing.  Readily removable fittings shall be provided at the end of all cross mains.  All cross mains shall terminate in 1¼ in. (31.8 mm) or larger pipe systems shall be arranged to facilitate flushing.  All branch lines on gridded systems shall be arranged to facilitate flushing.

5 Fire Fighting Systems CALCULATIONS

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.

Sprinkler Zone Limitations  The maximum area of any single sprinkler zone in a floor shall be not more than the floor area specified below. The water supply to the sprinklers supplied by any one sprinkler system riser or combined system riser shall be not more than the specified maximum floor area.  Where the floor area exceeds the limit as specified below, an additional water supply risers shall be proposed for every maximum sprinkler zone in each floor complete with sprinkler Alarm check Valve (ACV) assembly and riser isolation valve.  In addition, a floor zone control valve (ZCV) assembly shall be proposed at every floor where the tapping is taken from the sprinkler riser.  Alarm Check Valves (ACV) and Floor Zone Control Valves (ZCV) shall be located inside stair enclosure at a higher level than required ‘Headroom’ for the stairs.

Sprinkler Operating Pressure and Pipe Sizes: Sprinkler Operating Pressure:  The minimum operating pressure of any sprinkler for determining the water supply requirements shall be not less than 0.5 bar (7 PSI) in the light hazard occupancy and 1.0 bar (14.5 PSI) in the ordinary hazard occupancies.  The maximum operating pressure in a sprinkler system shall not be more than 12 bar.  Where higher operating pressure is used for the sprinkler system, all the sprinklers, pipes and fittings shall be rated for the higher operating pressure, however the operating pressure shall not be more than 16 bar in any case. Pipe Sizes:  The minimum pipe sizes shall be determined according to the hydraulic calculations. However, the minimum pipe sizes shall be not less than the diameters specified in the Table below.  However the number of sprinklers fed by the pipes having 65 mm diameter and above in a sprinkler zone may be permitted to increase subject to the submission of acceptable computerized listed hydraulic calculations according to the area protection limitations as specified.

Hydraulic Calculations Method  Computerized Hydraulic calculations shall be performed to determine the fire water demand, pressure and pipe sizes required for a sprinkler system installed in all types of occupancies.  The hydraulic calculation shall be performed using the Civil Defense listed and approved software. Following criteria shall be used for Hydraulic calculations.  Sprinkler system that is protecting an occupancy hazard that requires greatest water demand situated any where within the occupancy for the design density of discharge according to the occupancy classification.  Sprinkler system that is protecting an occupancy hazard that is located hydraulically farthest point from the source of fire water supply system within the occupancy for the design density of discharge according to the occupancy classification.  Sprinkler system that is protecting an occupancy hazard that is located hydraulically topmost point from the source of fire water supply system within the occupancy for the design density of discharge according to the occupancy classification.  The fire water source shall be selected based on the above criteria, whichever is the greater requirement.

Pipe Schedules Method :

Pipe Schedules Method :

Pipe Schedules Method :

Sprinkler Design Density & Water Supply Requirements  The minimum required design density of water discharge over the protected surface area shall be determined based on the occupancy and hazard classification.  However, If the fire water supply is combined for both sprinkler and stand pipe wet riser system, the fire water demand shall be established as follows:  In the buildings fully protected by an automatic sprinkler system, the fire water demand established for the wet riser system is permitted to serve sprinkler system without adding additional water demand in it.  If the wet riser system demand calculated exceeds the sprinkler system demand including the hose stream allowance, the larger of the two demand value shall be proposed depending on the hazard.

Water Demand Requirements Density/Area Curves.  The water supply for sprinklers only shall be determined from the density/area curves of Figure below.

Water Demand Requirements Density/Area Curves.

Water Demand Requirements  The minimum water demand requirements for a sprinkler system shall be determined by adding the hose stream allowance to the water demand for sprinklers.  The hose stream allowance and water specified in table 11.2.3.1.2.  The minimum water supply shall be available for the minimum duration specified in Table 11.2.3.1.2.



Classification of Commodities.











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:





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.