INSPECTION, TEST, AND MAINTENANCE REQUIREMENTS …

1 Question Two:How do you ensure that your hangar s foam/watersprinkler system is reliable?The reliability of the fire protection system is highlydependant on the quality of design, installation, andservice ( testing / inspection / MAINTENANCE ).Afoam/w ater deluge sprinkler system is generally theheart of most aircraft hangar fire protection systems. Itincludes fire pumps, foam pumps or bladder tanks,detection systems, deluge valves and other accessoryequipment. These components work together as a totalpackage to protect the hangar against the threat of the system is integrated, the design should beperformed by a fire protection engineer who has exper-ience in both suppression and detection systems. Theinstallation includes many contractors: general, electri-cal, mechanical, sprinkler, etc.

2 These contractors mustwork as a partnership to install an integrated fire pro-tection system that does not lead to the expense of falsedischarges or lack of operation in a fire , the most overlooked part of ensuring a reliablesystem is periodic testing , inspection and is important to test the system at regular intervals butalso to inspect on a weekly basis. These inspectionsand tests assure that the components are in full opera-tional condition and will perform in a fire condition asdesigned. NFPA 409 1995, Standard on AircraftHangars, requires inspection and testing at regularintervals. (See Figure 2 for actions and intervals forperiodic inspection , testing and MAINTENANCE .) Question Three:What is the purpose of a test manifold?

3 NFPA 409 1995 requires discharge testing every fiveyears. The installation of a testing manifold will reducethe time and expense of performing the test as well asminimize damage to unrelated hangar equipment thatcould occur in a test manifold on the foam/water sprinkler systemallows testing to be performed without discharging thefoam/water solution from the sprinkler heads them-selves. The test manifold verifies the proper mixture ofwater and foam concentrate developed by the propor-tioning equipment. This arrangement allows periodictesting without affecting electrical equipment, aircraftor other water sensitive equipment in the 1995, Deluge Foam Water Systems, indicates that test manifolds can be used for testing .

4 (See Figure 3 for configuration of piping for test mani-folds.)Question Four:Why is foam used and what does it add tothe fire protection of a hanger? fire fighting foam was originally developedin the 1930s to fight flammable liquid deluge systems alone will not suppressa large pool fire on the floor of a hangar. Thisis due to the very high heat release rate of alarge pool fire of flammable liquid in an air-craft hangar with a high roof structure. Thewater alone cannot cool the fuel to create firesuppression. Using foam, which is the aspira-tion of a water and foam concentrate, willsuppress the fire by blanketing the fuel andsmothering the flames as well as providingvapor suppression. Today there are many dif-ferent types of foam concentrates includingProtein, Fluoroprotein, Film-FormingFluoroprotein, Aqueous Film-Forming Foam,Alcohol-Resistant Concentrate AFFF andSynthetic Detergent (High/Medium-Expansion).

5 The foam concentrate is com-bined with water by mechanicalproportioning devices to a 3% or 6% solu-tion to form the foam/water there are several different types offoam concentrates, the most commonly usedis 3% AFFF or Aqueous aircraft hangar owners have convertedtheir water deluge systems to foam/waterdeluge sprinkler systems. NFPA 409 1995makes this conversion a little easier with afew concessions for the higher densities ofthese water deluge systems. The standardallows a reduction of the foam dischargeduration for the higher density up to 7 min-utes and waves the uniform dischargerequirement of 15% maximum variationbetween output of the sprinkler head Five:What is monitor protection and how can ithelp protect the aircraft hangar?

6 Monitors and their nozzles (sometimes calledwater cannons) discharge a stream of wateror foam/water solution covering a particulararea such as the under-wing area that couldbe obstructed by the overhead sprinkler sys-tem. (See Figure 4 for typical monitor andnozzle combination.)Fixed low-level nozzles or oscillating moni-tors are typically used as supplemental sys-tems to provide coverage for thoseobstructed areas created by large NFPA 409 1995 only allows anoverhead foam/water deluge for protection ofGroup I Hangars, it does allow alternatemethods if they can be proven to provide anequivalent level of protection. Hangars havebeen built and equipped with monitor noz-zles as protection in Group I this fire protection concept, Military is currently investigating theuse of floor level systems to replace the over-head foam/water deluge sprinkler I Hangars that have been equippedwith monitor nozzles as protection have beenaccepted by the local Authority HavingJurisdiction (AHJ) based on quick response(flame) detection and fast delivery of protection provided by the monitor noz-zles does not provide the wetting effect onthe structural steel that the overhead delugefoam/water system will provide.

7 However, ifthe foam/water solution can be appliedquickly enough, the fire is not expected togrow to a point where the steel structure willbe at risk from fire 4 NOTE: Details typical of deluge sprinkler system with bladder-type proportionerFIGURE 3 OPTION A(Controller after sprinkler valve)OPTION B(Controller after sprinkler valve) & Y. VALVE(Supervised)TESTCONNECTIONPROPORTIO NERCONTROLLERCONCENTRATEISOLATION & Y. VALVE(Supervised)WATER SUPPLYSPRINKLER VALVE(DELUGE)TOBLADDER TANKFROMBLADDER TANKTOSPRINKLERSTOSPRINKLERSWATER & Y. VALVE(Supervised)TESTCONNECTIONPROPORTIO NERCONTROLLERCONCENTRATEISOLATION VALVESPRINKLERVALVE(DELUGE)TOBLADDER TANKFROMBLADDER TANKINSPECTION, TEST, AND MAINTENANCE REQUIREMENTS FOR A FOAM-WATER DELUGE SYSTEM IN AN AIRCRAFT HANGAR(Adapted from NFPA 409 1995 Edition)FrequencyItemWeeklyMonthlyQuarte rlySemi-AnnualAnnualYear 5 fire PumpsFDFoam PumpFODO ptical DetectorsVFOS prinkler Alarm ValueVODeluge ValveVODW ater ReservoirsVConcentrate PumpsFODC ontrol ValvesVFFoam Proportioning DeviceVDControl PanelsVFOA larm TransmissionFHose StationsVDDrains (Floor)

8 VDFire DoorsVFGas DetectorsVFTamper SwitchFElectric and Pneumatic DetectorFOSupervisory AlarmsFManual Actuation StationsFVentilation System in Pits, FTunnels, DuctsPiping HangersVStrainersVFlow Indication SwitchOKEY: V =Visual InspectionF = Functional TestO=Operational TestD=Operational with Actual DischargeNOTE: All actions required Monthly will be required on the next level of time period , Annual but may move from a Visual V to a function F .FIGURE 2 Question Six:Who understands fire protection systemsfor aircraft hangers and how these systemswork?Ahangar fire protection system is complexenough to require specialized expertise. It isimportant to hire experienced engineers fortheir design and an experienced contractorfor installation, inspection and , the ultimate responsibility for theoperation of the fire protection systems lieswith the owner.

9 It is best to examine the engi-neer s and contractor s qualifications beforethey are hired to work on your system. Inaddition, you will need to become familiarwith the REQUIREMENTS of your system to veri-fy that the installation and service people areperforming all tasks required in accordancewith the AHJ as well as the insurance place to find qualified contractors orengineers is to ask your colleagues. Anotheroption is to consult with your insurance car-rier or insurance broker. Insurance carriers orbrokers are responsible for many facilitiesand have worked with many different con-tractors and engineers. In many cases, thefire equipment manufacturers of the foam orsprinkler equipment conduct training coursesfor contractors and engineers and can be asource of information.

10 It is wise to develop aspecific qualification request package thatrelates to your REQUIREMENTS . Ask for infor-mation on the company s staff, experienceand project history. It is vital to get contactnames on past projects to verify their abilityand quality. Develop a list of questions foreach company you interview and target theactual task they would be asked to as much detail on testing and inspec-tion protocols as possible from upgrade the industry s technical capabili-ties, The National Institute For CertifiedTechnicians (NICET) has developed a pro-gram to certify technicians on inspection andtesting of fire protection systems. This willassist owners in identifying qualified con-tractors with personnel who are certified toperform the testing and inspection of fireprotection systems.