fire / smoke dampers - grada dampers.pdf · smoke, like air, will pass through a ventilation...

S P E C I F I C A T I O N S S U B J E C T T O C H A N G E

Te l : Sa les 01942 889555 I Web: www.grada.co.uk

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FIRE / SMOKE DAMPERSSERIES 600

Series 600 Fire/Smoke DampersSmoke, like air, will pass through a ventilation system. Thepurpose of a smoke damper, is to prevent the progressionof smoke through the system. To be truly effectivetherefore, a smoke damper must have low leakage factor.A combination fire/smoke damper has more demandingcriteria, it must maintain its physical integrity in the mostdemanding conditions of temperature, and throughoutthis period it must maintain a low leakage rate, if it is notcapable of doing this, then it cannot be an effectivefire/smoke damper. Quite definitely, simply adding adevice to a fire damper, which will initiate operationfollowing a signal from a smoke sensor does not make afire damper a smoke damper. The absence in the U.K. ofspecific smoke leakage standards and criteria haspermitted manufacturers to self define what a smokedamper is. Careful consideration and evaluation shouldtherefore be made when choosing your fire/smokedamper.

Grada UK series 600 fire/smoke dampers specificallyaddress leakage rates at ambient and elevatedtemperatures. The blades are roll-formed from 16 msgsteel and the casings are 18 msg steel,. complete withwelded corners. The linkage is concealed out of theairstream completely, within the double skin casing. Series600 fire/smoke dampers have successfully passed a sixhour fire endurance test.

Series 600 Fire/Smoke Damper, Model A,shown with sleeve extension and shaft formotor. Various options are available includingthermal links, electric motors, micro switches,and pneumatic actuators.

Precise roll formed construction. Double skin galvanised steel casing,16 msg galvanised steel blades (stainless steel optional).

Fire endurance tested for 6 hours: Warrington Fire Research Centre, 85476, Part 20.

Stainless steel springs.

Stainless steel jamb seals.

Available with micro switches for blade status indication.

Available with HEVAC/HVCA installation frames. In compliance with HEVAC 6/5/83 2002.

Casing manufactured in accordance with the requirements ofDW 142.

MODEL AFor square or rectangular,spigot connections. Sizesfrom 200mm to 1000mm

width or height.

MODEL CFor round, spigot

connections. Sizes from200mm to 1000mm

diameter.

MODEL DFor flat oval, spigot connections.

Sizes from 200mm to 1000mmwidth or h.

Models



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Why Use A Fire/Smoke Damper?Fire/smoke dampers (as opposed to ordinary firedampers) are needed whenever the designer of anair handling system has to address the problems oflife safety in addition to preventing and controllingproperty loss as a result of fire. Fire/smoke dampers,by definition, have to prevent and retard themigration of smoke (products of combustion) througha duct system as well as preventing flame frompenetrating from one side of a fire barrier to theother. It is essential that fire/smoke dampers aremeasured as to their ability to seal against elevatedtemperature smoke (not merely an air leakage test) aswill be encountered in a real fire. At present, thereare no British Standards which specifically evaluatefire/smoke dampersfor leakage.

At this particular stage in the evolution of teststandards in the U.K. there are, opportunities formanufacturers to self define what are "fire/smokedampers". Most of these devices are merely firedampers equipped so as to be able to beactuated from a smoke detector. The damper itselfmay not have any particular smoke retardationcharacteristics, but simply close upon a remotesignal. This ability does not make it a fire/smokedamper except in name only. To be a "fire/smokedamper" a fire and smoke isolation device must,we think, be designed and tested for actual fireand smoke conditions. Series 600 fire/smokedampers have been purpose built for these realfire conditions.

FIRE / SMOKE DAMPERS



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FIRE / SMOKE DAMPERSPERFORMANCE

Fire TestsGrada UK series 600 fire/smoke dampers have beentested to British standard 476, Part 20, by the WarringtonFire Research Centre, Test No. 49270 Warrington, Cheshire.These tests were successfully conducted for six hours of fireendurance measured against the standardtime/temperature curve (see below). The furnace wascontrolled so that its mean temperature complied withthe curve as required by BS 476, Part 20. The damperswere evaluated against the following criterion: "7.1.1 -integrity BS 476, Part 20, 1987 requires that there is nocollapse of the specimen, no flaming on the unexposedsurface and no loss of impermeability." These requirementswere satisfied throughout the 6 hours duration of the tests.

This photograph was taken during a successful6 hour fire endurance test on series 600fire/smoke damper. In addition to fire exposure,series 600 fire/smoke dampers have beentested for leakage at elevated temperaturesand various supplemental reliability tests, (seefollowing pages).



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Airflow leakage under positive pressurethrough closed damper. This graph showsthe values for the worst case of four extremeaspect ratios; max x max, min x min, max xmin, and min x max.

Pressure loss values depend on duct areablockage and vary with damper sizes. Thegraph above is for a typical size damper of600mm x 600mm. Individual damper lossesmay vary somewhat from this size.

Pressure LossAnother important design consideration is pressure loss.Dampers restrict airflow and therefore cause pressurelosses. Allowances must be made for these losses by thesystem designer in calculating total system loss pressureto insure proper fan selection and air infiltration. The airperformance of a damper may be described by thepressure drop across the damper for a given airflow ratethrough the face area of the damper. This performanceis expressed as velocity through the damper face areaversus measured pressure drop. The major factoraffecting pressure loss is the percentage of duct areablocked by intrusions of the various damper parts. Theminimization of this blockage is critical in good damperdesign and is achieved in our series 600 fire/smokedampers by concealing the damper linkage, andminimizing the number of blades.

LeakageEqual in importance to its ability to endure a fire is afire/smoke damper's ability to seal against the migrationof smoke. Series 600 fire dampers have been thoroughlytested for leakage against a range of static pressuresand at elevated temperatures. The requirement fortesting at elevated temperatures is essential to enablethe designer of the air handling system to specifydampers safe in the knowledge that they will performunder real-fire conditions. Blade edge and jamb sealsmust be designed and tested to not only withstandhigher temperatures, but also to endure withoutdeterioration 5000 cycles and opening and closingagainst air flow. The graph (opposite) shows the resultsof tests conducted on series 600 fire/smoke dampers asmeasured against typical "fire/smoke dampers"equipped with jamb seals only. Leakage is expressed aslitres/second/ metres squared of a duct area across arange of differential pressures.




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CorrosionReliability is an essential design consideration forfire/smoke dampers as they are life safety devicesand are called upon to perform in extremeenvironmental conditions. Moving parts must bekept free from the adverse effects of corrosion toensure rapid and free movement. Operatingsprings are of stainless steel construction. Series 600fire/smoke dampers utilize zinc dichromate platingon axles and cranks and oil impregnated bronzebearings. In addition, stainless steel jamb seals arestandard and all welds are painted. Series 600fire/smoke dampers have successfully passed saltspray corrosion tests where the dampers weresubjected to the effects of a 20% salt spray for 120hours, after which time, the dampers successfullyclosed and latched.

Reliability TestsIn addition to the tests described above, series 600fire/smoke dampers have been subjected tosevere supplemental reliability tests. The dampershave been tested for 5000 operating cycles(open/close/open) to simulate wear over the lifetimeof the air handling system. The dampers havebeen evaluated as to their ability to operate underairflow conditions and to determine torquerequirements for given damper sizes. Both closingtorque and breakaway torque were measured toinsure operational reliability. Tests have beenconducted to insure that there is no flaming on theunexposed side of the dampers during fireexposure. Stainless steel springs were cycled 5000times. Finally, every series 600 fire/smoke damperare bench tested in our factory to insure for freemovement of parts, motor/actuator suitability andadjustment, and precision tolerances of all seals.



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Model A - Damper Spigot Supplied - 6mm Under Nominal Duct height and Width

Model C - Damper Spigot Supplied - 3mm Under Nominal Duct Diameter

Model D - Damper Spigot Supplied - 3mm Under Nominal Duct Height and Width

(All Dimensions are Given in mm)

FIRE / SMOKE DAMPERSDIMENSIONAL DATA : SERIES 600



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FIRE / SMOKE DAMPERSDIMENSIONAL DATA : SERIES 600

Model A - Overall width of installation frame is duct width +104mm

Dampers With Hevac Installation Frames

Model C - Overall width of installation frame is duct width +148mm

Model D - Overall width of installation frame is duct width +148mm



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SpecificationCombination fire/smoke dampers shall be series 600as manufactured by Grada UK All fire/smokedampers shall have been successfully fire endurancetested for 6 hours. Series 600 dampers shall becomplete with high temperature blade edge sealsand have been tested for leakage at elevatedtemperatures Leakage shall not be greater than 40

litres/second/metre duct area at a differentialpressure of 1000 Pa. All series 600 fire/smokedampers shall have been tested for corrosion in a20% salt spray for 120 hours. Jamb seals and springsshall be of stainless steel construction and all axlesand cranks shall be plated with zinc dichromate toresist corrosion.

Ordering Information

FIRE / SMOKE DAMPERSSPECIFICATION

fire / smoke dampers - grada dampers.pdf · smoke, like air, will pass through a ventilation...

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