Dampers 1 3 Section Index Introduction, Authority/ Certification, Fire Rating and Approvals 2 Marine Equipment Directive 4 FGD Fire and Gas Damper 5 MFD Fire and Gas Damper 7 LFD Fire and Gas Damper 9 Control Options 11 MFDS(P) Fire Suppression Damper (Pneumatic) 13 PRDF(G) Fire Suppression Damper (Gravity) 15 Isolation Damper 16 Volume Control and Modulating Damper 18 Fan Inlet Guide Vane Damper 20 Non-Return/Pressure Relief Damper 21 Butterfly Non-Return Damper 22 BPD Blast Protection Damper 23
Transcript
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3Section
Index
Introduction, Authority/Certification, Fire Ratingand Approvals 2
Marine Equipment Directive 4
FGD Fire and Gas Damper 5
MFD Fire and Gas Damper 7
LFD Fire and Gas Damper 9
Control Options 11
MFDS(P) Fire SuppressionDamper (Pneumatic) 13
PRDF(G) Fire SuppressionDamper (Gravity) 15
Isolation Damper 16
Volume Control andModulating Damper 18
Fan Inlet Guide Vane Damper 20
Non-Return/PressureRelief Damper 21
Butterfly Non-Return Damper 22
BPD Blast ProtectionDamper 23
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Fire & Gas Dampers
Introduction
Fire & Gas Dampers are used inventilation systems to prevent thespread of flame and/or smokebetween divisions.
Wozair manufacture three types ofFire & Gas Damper depending on theapplication and specification. Alldampers have been independentlytested and have third party certification.
Each type of Fire & Gas Damper canbe supplied in stainless steel grades304L (1.4307), 316L (1.4404) and(1.4432) Mo>2.5% or carbon steel andcan be provided with numerouscontrol systems including pneumatic,electric and manual latch operation.
All dampers can be supplied to suitrectangular or circular ducts.
Authority/Certification
FGDThe damper has been subject to a 2hour Hydrocarbon fire test and iscertified by Lloyds Register ofShipping, Det Norske Veritas andBureau Veritas for use in ‘H-0’–‘H-120’Bulkhead and Deck Divisions with theducting suitably insulated.
MFDThe damper has been fully tested tothe Solas Rules/FTP Code ResolutionA754(18) together with its relevantmeans operation and also BS476Pt20 for 4 hours. The damper iscertified by Lloyds Register ofShipping and carries the MED/MRAmark of conformity. The damper issuitable for use in ‘A-0’–‘A-60’Bulkhead and Deck Divisions with theducting suitably insulated. For smokeclearance the damper is certified at300°C for 1 hour for high temperatureoperation. The damper is also typeapproved by DNV, BV, ABS, RINA, GLand USCG under the MarineEquipment Directive/MutualRecognition Agreement.
LFDThe damper has been fully tested tothe Solas Rules/FTP Code ResolutionA754(18) together with its relevantmeans operation and also BS476Pt20 for 4 hours. The damper iscertified by Lloyds Register ofShipping and carries the MED/MRAmark of conformity. The damper issuitable for use in ‘A-0’–‘A-60’Bulkhead and Deck Divisions with theducting suitably insulated. For smokeclearance the damper is certified at300°C for 1 hour for high temperatureoperation. The damper is also typeapproved by DNV, BV, ABS, RINA, GLand USCG under the MarineEquipment Directive/MutualRecognition Agreement.
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3Section
Fire Ratings and Approvals
Offshore and Marine Fire Divisions arenormally classified as ‘A’ or ‘B’ whichrelate to temperature limits that mustbe adhered to on the non-fire side ofthe division. The divisions areinsulated within dimensionalparameters defined in Solas Rules, toreduce the temperature rise to safelimits for a period of 60 minutes overboth the damper case and the surfaceof the insulation. Where a fire damperis installed within the duct length asdefined in Solas Rules then thesesafe temperature limits must bemaintained, as the damper is a metalstructure then the only way to controland limit temperature rise is toinsulate to the same standard as thesurrounding ductwork. Thetemperature rise being measured overthe external surface of the insulation.
Installations:Typical installation and insulationdetails are included in the LloydsCertification. However, where dampersare to be installed within thedimensional parameters defined inSolas Rules, the following applies:
Class ‘B’ – For a damper to pass aclass ‘B’ approval, it must maintain itsintegrity and resist the passage offlame for a period of greater than 30minutes, the temperature rise on theexternal surface of the damper mustnot rise higher than 140°C aboveambient during the time period norshould the temperature at any point onthe insulation rise more than 225°Cduring the same time period.
Class ‘A’ – Classification is commonfor Offshore applications: FireDampers rated for ‘A-0’ classdivisions are required to pass a 1 hourfire test. Fire dampers for ‘A-60’divisions must maintain integrity andresist the passage of flame for aperiod of greater than 60 minutes, thetemperature rise on the externalsurface of the damper must not risehigher than 140°C above ambientduring the time period nor should thetemperature at any point on theinsulation rise more than 180°Cduring the same time period.
Wozair Fire Dampers fulfil theserequirements when suitably insulated.
Class ‘H-0’–‘H-120’ Fire Divisions– Wozair FGD Fire Dampers havebeen tested and approved to meet thisstandard which involves a 2 hour firetest to the hydrocarbon temperaturecurve.
It must be clearly understood that aFire Damper can only carry an ‘A-0’ or‘H-0’ classification by itself and oninstallation with suitable insulation (byothers) the higher classification will beachieved.
Enclosures can be pre-insulatedwhere required. Approval forinstallation must be gained from theappropriate certifying authority.
The Marine Equipment Directive 96/98/EC(MED) as amended by directive 98/95/EC came into force on January1st 1999 and covers the safetyaspects of equipment (such as FireDampers for Fire Protection) carriedon ships registered under the flags ofthe European Union Member States.
Recognition by the United States ofAmerica/USCG came into force in July2004 under the EU-US MutualRecognition Agreement of MarineEquipment.
The Directive has been a mandatoryrequirement since January 1st 2001.
For Marine vessels registered to anEU member state, Wozair Fire andGas Dampers carry the MarineEquipment Directive/MutualRecognition Agreement (MED/MRA)Wheelmark.
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3Section
FGD Fire and GasDamper
Typical Applications
Heavy duty, aggressive processenvironments where integrity, strengthand corrosion resistance are ofprimary importance.
Description
‘A-0’–‘A-60’ and ‘H-0’–‘H-120’Deck and BulkheadApplications
CasingThe 300mm deep frame is formed intorigid channel sections that are fullywelded, sheet steel thickness rangefrom 3-10mm. Damper over 1200mmwide have welded vertical mullionsand dampers over 1200mm high havehorizontal transoms. Flange drillingsare in accordance with the Wozairstandard or to specific clientrequirements. Where it is difficult toaccess the bolt holes behind thecontrol enclosure, welded nuts will beprovided. Casings are provided with20mm diameter lifting holes asstandard.
Dampers smaller than 150mm orrequired for circular connection aresupplied with either 3mm thickstudded transition plates stitch weldedto each side or circular spigots 50mmdeep. This increases the insertiondepth by either 6 or 100mm.
BladesThe blades are double skin aerofoiltype manufactured from 1.5mm thickstainless steel sheet and aresynergically plug welded to 19mmdiameter continuous shafts. Bladeshafts rotate in high temperature, oilimpregnated, sintered bronzebearings, fitted into welded housings.Other bearing options are available.
For nuclear applications where thecasing penetrations need to besealed, lip seal bearings are fitted into
the bearing housing on the drive side.Blind bearing bosses are fitted on thenon-drive side. Refer to cataloguesection 7.
LinkageDampers over 300mm high havemultiple blades that are linkedtogether to provide opposed motion.Robust blade links are welded to thedrive shafts and connected together byflat bar and stainless steel pins. Thelinkage arrangement is containedwithin the flanges of the damperframe.
The drive shaft is extended and fittedwith a welded precision machinedboss for connection to the actuatingmechanism.
As an option, particularly for nuclearapplications, removable linkages canbe specified whereby the blade linksare welded to bosses that aresecurely pinned to the shafts.
Removable linkage cover plates arefitted where requested.
SealsTight air shut off is achieved byprecision roll formed sprung stainlesssteel grade 316L (1.4404) side sealsand welded top and bottom angleblade stops.
Controls for OperationPneumatic Actuator, Electric Actuator,Temperature Sensitive Trigger, ManualSpring Release, Latching Mechanism.For full details see Control Section.
Bearings: Roller or ball raceEarth Continuity BossesLifting LugsPre-insulated controls enclosureClient specific requirements
Leakage RatesFire and Gas dampers are designedto minimise leakage. Extensive testingon standard production single moduledampers has proven a mean leakagerate of 0.040 m³/sec/m² at adifferential pressure of 2000Pa and0.002 m³/sec/m² at a differentialpressure of 50Pa. However, if lowerleakage rates are required as aspecial requirement, please consultour engineering department.
Nominal Clear inside duct dimensionsDuct Size: ‘Quote’ (Width x Height)
Order Code Example:FGD/316L/3.0/500W/300H/300D
Performance
Full aerodynamic performance data ispresented below and is based ontests concluded.
Total Pressure Loss (PT)
This is the difference in pressuremeasured across the fire damper,when the blades are fully open.
Dimensional Limits
The minimum damper size is 150mmwide x 150mm high. The maximumsingle module size is 1200mm wide x1200mm high. For larger sizes theaddition of mullions and transomsallow a maximum size of 3950mmwide x 2500mm high for a single piecedamper.
Larger sizes are subject to case bycase approval by the certifyingauthority.
Ordering
Quantities, control requirements andother special requirements to bestated separately.
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3Section
MFD Fire and GasDamper
Typical Applications
Oil and Gas, Marine, Nuclear, Processand General Ventilation Systems.
Description
‘A-0’–‘A-60’ Deck andBulkhead Applications
CasingThe damper frame is formed fromsheet steel into rigid channel sectionsthat are either fully welded or weldedand riveted together. Dampers over1200mm wide have welded verticalmullions and dampers over 1200mmhigh have horizontal transoms. Flangedrillings are in accordance withWozair’s standard or to specific clientrequirements. Where it is difficult toaccess the bolt holes behind thecontrol enclosure, welded nuts will beprovided. Casings are provided with20mm diameter lifting holes asstandard.
For circular ducts, mounting transitionpieces are supplied with either casethickness transition plates stitchwelded to each side of the damper orcircular spigots 50mm deep. Thisincreases the insertion depth by twicethe case thickness or 100mm.
BladesThe blades are double skin aerofoiltype from 1.2mm thick steel and areplug welded or bolted to 19mmdiameter solid shafts. Blade shaftsrotate in high temperature, oilimpregnated, sintered bronzebearings, fitted into the damper frame.For nuclear applications, where thecasing penetrations need to besealed, lip seal bearings are fitted intoa bearing housing on the drive side.Blind bearing bosses are fitted on thenon-drive side.
LinkageDampers with multiple blades that arefitted with a linkage to provide anopposed motion. Robust blade linksare welded to the drive shafts andconnected together by flat bar andstainless steel pins. The linkagearrangement is contained within theflanges of the damper frame.
The drive shaft is extended and fittedwith a welded precision machinedboss for connection to the actuatingmechanism. As an option, particularlyfor nuclear applications, removablelinkages can be specified whereby theblade links are welded to bosses thatare securely pinned to the shafts.
Removable linkage cover plates arefitted where required.
SealsTight air shut off is achieved byprecision roll formed sprung stainlesssteel grade 316L (1.4404) side sealsand welded top and bottom angleblade stops.
Controls for OperationManual Spring Release, LatchingMechanism, Pneumatic Actuator,Electric Actuator, TemperatureSensitive Trigger. For full details seeControl Section.
OptionsMaterials: Stainless Steel 304L
(1.4307), 316L (1.4404)and (1.4432) Mo>2.5% orGalvanised Mild SteelFrames in a range ofthickness from 2-10mm
Case depth: 200-300mmRemovable linkageContinuous blade shaftsBearings: Roller or ball raceEarth Continuity BossesLifting LugsPre-insulated controls enclosureClient specific requirements
Leakage RatesFire and Gas dampers are designedto minimise leakage. Extensive testingon standard production single moduledampers has proven a mean leakagerate of 0.040 m³/sec/m² at adifferential pressure of 2000Pa and0.002 m³/sec/m² at a differentialpressure of 50Pa. However, if lowerleakage rates are required as aspecial requirement, please consultour engineering department.
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Dimensional Limits
Bulk Head Applications: Theminimum size is 100mm wide x100mm high. The maximum singlemodule size is 1200mm wide x1200mm high. For larger sizes theaddition of mullions and transomsallow a maximum size of 2500mmwide x 2100mm high.
Deck Application: The minimumsize is 100mm wide x 100mm high.The maximum single module size is1200mm wide x 1200mm high. Forlarger sizes the addition of a mullionallows a maximum size of 2500mmwide x 1000mm high for a single piecedamper. Larger sizes are subject tocase by case approval by the certifyingauthority.
Nominal Clear inside duct dimensionsDuct Size: ‘Quote’ (Width x Height)
Order Code Example:MFD/316L/2.0/500W/300H/200D
Performance
Full aerodynamic performance data ispresented below and is based ontests conducted.
Total Press Loss (PT)
This is the difference in pressuremeasured across the damper, whenthe blades are in the fully openposition.
Ordering
Quantities, control requirements andother special requirements to bestated separately.
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3Section
LFD Fire and GasDamper
Typical Applications
Marine, Process and DW144 GeneralVentilation Systems.
Description
‘A-0’–‘A-60’ Deck andBulkhead Applications
CasingThe damper frame is a welded andriveted construction with integral50mm folded flanges from 1.5mmthick steel. The drive side casingsection is provided with a return flangeto facilitate the mounting of theactuator bracket. For dampers to beconnected to circular ductwork,transition plates with 20mm spigotconnectors are provided.
BladesSingle skin 1.5mm thick steelinterlocking blades are securelyriveted to continuous 19mm diametertubular shafts. Shafts rotate in flaredbearing holes within the damper caseand are linked externally to provide aparallel motion. The drive shaft isextended for connection to theactuator.
SealsTight air shut off is achieved byprecision roll formed sprung stainlesssteel grade 316L (1.4404) side sealsand welded top and bottom angleblade stops.
Controls for operationPneumatic ActuatorElectric ActuatorTemperature Sensitive TriggerManual Spring ReleaseLatching MechanismFor full details see Control SectionPage 11.
OptionsMaterials: Stainless or Galvanised Mild
Steel Frames in a range ofthickness (minimum1.5mm)
Case depth: 200mmEarth Continuity BossesLifting LugsPre-insulated controls enclosureClient specific requirements
Leakage ratesFire and Gas dampers are designedto minimise leakage. Extensive testingon standard production single moduledampers has proven a mean leakagerate of 0.060 m³/sec/m² at a differentialpressure of 2000Pa. However, if lowerleakage rates are required as aspecial requirement, please consultour engineering department.
Nominal Clear inside duct dimensionsDuct Size: ‘Quote’ (Width x Height)
Order Code Example:LFD/316L/1.5/500W/300H/200D
Dimensional Limits
The minimum damper size is 150mmwide x 150mm high. The maximumsingle module size is 800mm wide x800mm high.
Performance
Full aerodynamic performance data ispresented below and is based ontests conducted.
Total Press Loss (PT)
This is the difference in pressuremeasured across the damper, whenthe blades are in the fully openposition.
Ordering
Quantities, control requirements andother special requirements to bestated separately.
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3Section
Control Options
With over two decades of experience,Wozair have supplied countless FireDamper control systems to suitvarious applications. Our experienceenables us to design control systemsto meet particular requirements. Thefollowing standard systems aredetailed as a guide for customers andspecifiers, and can be applied to anyof the fire dampers in our range.
Client specific controls can besupplied on request. Depending oncomplexity and customer’srequirements, Fire Damper controlswill either be supplied fitted inside aremovable enclosure or fitted to aremovable plate mounted on the driveside of the damper. In additionsseparate fire damper control panelscan be supplied. For Marine MED/MRAapplications Wozair MFD and LFDDampers have been fire tested with acomplete range of actuators and firetrigger devices to comply withSolas Rules and carry theLloyds/MED/MRA approval andcertification.
Pneumatic ActuationAn air to open, spring return to closepneumatic actuator is fitted withnumerous options for valves andelectrical items. Some options aredetailed below:
ActuatorsActuator anodised painted or PTFEcoated aluminiumCompositePainted steelStainless steel
Valves & PipeworkBrass or stainless steelSolenoid valves for Safe orHazardous areasFrangible bulb operated valveManual test valvePilot operated valveQuick exhaust valveNon-return valve(for use with Reservoir/Black Start)
Electric ActuationA power open spring return electricactuator is fitted. For safe areaapplications the actuator will normallybe a Belimo BF type, and forhazardous area shall be Schischektype. If the damper is specified with itsown frangible trigger, for safe areasthe Belimo actuator will be fitted with aBelimo thermal sensor. For hazardousareas a rated switch will be operatedupon rupture of the frangible bulb orazeotropic sensor.
Damper operating times for electricactuation are as follows:
Standard Belimo – open 180s, close16s Special Safe Area – open 180s,close <3s
Schischek – 3s or 10s, close 3s or10s adjustable on site.
Both Belimo and Schischek actuatorscan be supplied with integral auxiliaryswitches for remote indication ofdamper status. The actuators aresupplied with flying leads which caneither be terminated in a junction boxfitted to the damper or installed onsite.
Manual LatchThe damper is manually latched in theopen position at the damper, with theblades held open against returnsprings fitted to the non-drive end ofeach shaft. De-latching and henceclosing of the damper is initiated byeither rupture of the frangible bulb,operation of a pneumatic cylinder byinert gas or interruption of electricalpower to a holding electro-magnet.
Local visual indication of damperstatus is provided by a pointer. Ifrequired, remote damper status isprovided by limit switches cabled backto a local junction box which shalleither be for safe or hazardous areadepending on the application.
Damper closing times for manuallatch dampers are less than 3seconds.
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Examples of ancillaryequipment options:
Position IndicationLimit switches suitable for Safe orHazardous areas. Proximity sensorsfor Safe or Hazardous areas. Switchboxes, Local pointers, Indicatorbeacons
Junction BoxesFor terminating solenoid valves andposition switches, suitable for Safe orHazardous areas, manufactured fromGRP, ABS, cast iron or stainless steel
InsulationDampers can be provided with theinsulation between the controlsenclosure and the casing pre-fitted.This eliminates the task of applyinginsulation between the casing andcontrols enclosure on site, and alsoensures that the controls are fullyaccessible for maintenance afterinsulations. The other three sides ofthe damper shall be insulated in-situby others.
Fireman’s Control PanelsFire damper control panels can besupplied where there is a need tocontrol a group or “zone” of dampersfrom a common point. Such panelscan be fitted with control valves andinstrumentation to suit specificrequirements. As standard the panelis manufactured in stainless steel 316and designed in accordance withIP55.
AuxiliaryCable glands suitable for safe orhazardous areas. Stainless steel tagplates for electrical items and valves.
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3Section
MFDS(P)Fire SuppressionDamper –Pneumatic
Typical Applications
Building Services Fire SuppressionSystems.The Damper is Fire Rated to BS476for 4hours.
Description
CasingThe damper frame is formed fromsheet steel into rigid channel sectionsthat are either fully welded or weldedand riveted together. Dampers over1200 mm wide have welded verticalmullions and dampers over 1200mmhigh have horizontal transoms. Flangedrillings are in accordance with theWozair standard or to specific clientrequirements. Where it is difficult toaccess the bolt holes behind thecontrol enclosure, welded nuts will beprovided. Casings are provided with20 mm diameter lifting holes asstandard.
BladesThe blades are double skin aerofoiltype from 1.2 mm thick sheet steel andare welded or bolted to 19 mmdiameter shafts. Blade shafts rotate inhigh temperature, oil impregnated,sintered bronze bearings, fitted intothe damper frame. The damper freearea is a function of size that istypically 75 to 85% of the area of theduct.
LinkageDampers with multiple blades arefitted with a linkage to provide anopposed motion. Robust blade linksare welded to the drive shafts andconnected together by flat bar andstainless steel pins. The linkagearrangement is contained within theflanges of the damper frame.
The drive shaft is extended and fittedwith a welded precision machinedboss for connection to the actuatingmechanism.
Removable linkage cover plates arefitted where required.
SealsTight air shut off is achieved byprecision roll formed sprung stainlesssteel grade 316L (1.4404) side sealsand welded top and bottom angleblade stops.
Controls for OperationThe MFD Damper is designed to openon release of the fire suppressionagent which also provides the energysource to operate the actuator.
Timer valves control the speed ofopening the damper (0.5 to 6seconds) and the period of thedamper remaining in the openposition (35 to 90 seconds) to allowover pressure to be exhausted fromthe room before closing andmaintaining fire integrity. Localpointers indicate open and closedstatus. Actuation is pneumatic poweropen, spring return, rated for amaximum air pressure of 10 barg.Note: The fire suppression agentdischarge pressure that is typically200 barg, must be regulated to the 8barg operating pressure of theactuator. This is the responsibility ofthe installer.
OptionsMaterials: Stainless or Galvanised Mild
Steel Frames materialthickness 2 mm
Case Depth: 200-300mm ContinuousBlade shaftsEarth Continuity BossesLifting LugsClient specific requirements
Leakage RatesFire and Gas dampers are designedto minimise leakage. Extensive testingon standard production single moduledampers has proven a mean leakagerate of 0.040 m³/sec/m² at a differentialpressure of 2000Pa and 0.002 m³/sec/m² at a differential pressure of 50Pa.However, if lower leakage rates arerequired as a special requirementplease consult our engineeringdepartment.
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Dimensional Limits
Bulk Head Applications: Theminimum size is 100mm wide x100mm high. The maximum singlemodule size is 1200mm wide x1200mm high. For larger sizes theaddition of mullions and transomsallow a maximum size of 2500mmwide x 2100mm high.
Deck Application: The minimumsize is 100mm wide x 100mm high.The maximum single module size is1200mm wide x 1200mm high. Forlarger sizes the addition of a mullionallows a maximum size of 2500mmwide x 1000mm high for a singlepiece damper.
Larger sizes are subject to case bycase approval by the certifyingauthority.
Nominal Clear inside duct dimensionsDuct Size: ‘Quote’ (Width x Height)
Order Code Example:FDSF(P)/316L/2.0/500W/300H/200D
Performance
Full aerodynamic performance data ispresented below and is based ontests conducted.
Total Pressure Loss (PT)
This is the difference in pressuremeasured across the fire damper,when the blades are fully open.
Ordering
Quantities, control requirements andother special requirements to bestated separately.
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3Section
PRDF(G) FireSuppressionDamper
Typical Applications
General Building Service FireSuppression Systems wherepressure relief is required by non-firerated dampers providing arudimentary level of control. Thefollowing design features have beenincluded:• For use in horizontal ducts or
CasingThe damper frame is formed fromstainless or galvanised sheet steel2mm thick into rigid angle section thatare plug welded and riveted together.Stainless steel or galvanised mildsteel 2mm thick angle blade stops areprovided at the top and bottom in orderto achieve an effective seal betweenthe casing and the blades.
BladesSingle skin stainless steel orgalvanised mild steel (2.0mm thick)are riveted to continuous tubularspindles. The spindles rotate in igusmoulded bearings. The blades areindividually mounted in the frame andare free to independently move torelieve room pressure. The damperfree area is a function of size that istypically 50% of the area of the duct.
At normal room pressure the bladesare designed to hang in the fullyclosed position, to prevent anybackflow of air into the room oroperating area. On discharge of theinert gas fire extinguishant the bladesopen to relieve pressure preventing
damage to the fabric of the building,until the blades close to retain theextinguishant and provide for firesuppression. It should be noted thatno provision is available for the effectof pressurisation to the back face ofthe damper, which would be aconsideration for instance should theunit be installed into an exterior wallwith exposure to wind etc. However,additional cowls or louvers can besupplied to minimise these effects.
OptionsOilite bearingsCover grilles (aluminium orstainless steel)External weather louvresClient specific requirements.
Type PRDFS(G) Duct Width 500W
Material 316L Duct Height 300H
Case Thickness 2.0 Case Depth 200D
Type Wozair: Pressure Relief FireSuppression Damper
Nominal Clear inside duct dimensionsDuct Size: ‘Quote’ (Width x Height)
Order Code Example:PRDFS(G)/316L/2.0/500W/300H/200D
Ordering
Quantities, surface finish and otherspecial requirements to be statedseparately.
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Isolation Damper
Introduction
A range of high integrity dampers hasbeen designed to meet therequirements of the oil and gas,nuclear and process industries, wherecorrosion resistance and mechanicalintegrity are of prime importance. Thefollowing design features have beenincluded:• Continuously welded construction• Opposed blade motion• Low casing leakage• Low blade leakage• Low airflow resistance• Low noise generation• Manual, pneumatic,
or electric operation• Wide range of materials
and controls• Excellent corrosion resistance
Description
CasingThis is a continuously welded channelsection construction and is availablein a range of materials and thickness.Typically: Stainless steel (1.5 mm to3.0 mm thick) grade 316L or 304, mildsteel, galvanised after manufacture(3.0 mm or 5.0 mm thick) or pre-galvanised steel. Angles with closedcell gaskets are fitted at the top andbottom as well as stainless steelgrade 316L (1.4404) precision rollformed sprung side seals in order toachieve an effective seal between thedamper case and the blades.
BladesThese are typically of stainless steelgrade 316L/304 or pre-galvanisedsteel. They are of double skin aerofoilsection. Blades are riveted tocontinuous tubular spindles. Thespindles rotate in acetal resin bushesand are linked externally to provideopposed blade motion.
Control MechanismsManual Isolating Damper: This isoperated by a robust adjusting handlewith a locking device which movesacross a quadrant plate. Moving thehandle through 90° moves the bladesfrom the fully open to the fully closedposition, thereby enabling the unit tobe used for volume control purposesif necessary.
Pneumatic and ElectricIsolating Dampers: These areoperated by actuators which move theblades from fully open to fully closed.
The actuator is controlled by either apneumatic or electric signal. Micro-switches indicating blade position arealso available. These units aredesigned to be fully open or fullyclosed. If intermediate blade positionsare required a modulating controldamper should be incorporated inthe system.
Control OptionsRefer to details in the Controls Section.
OptionsThe following options can beincorporated if required.Oil impregnated sintered bronzebearings in place of acetal.Reduced cost riveted/welded/sealedconstruction.Heavy duty 1.5 mm double skin bladeswelded to continuous solid shafts.Core depth: 200-300mmBearingLifting lugsEarth bossesClient specific requirements
Modifications to meet specific clientspecifications eg. BNF Plc NF.
Nominal Clear inside duct dimensionsDuct Size: ‘Quote’ (Width x Height)
Order Code Example:MID/316L/2.0/300W/300H/300D
Leakage Rates
Isolation damper are designed tominimise leakage. Extensive testingon standard production single moduledampers has proven a mean leakagerate of 0.040 m³/sec/m² at adifferential pressure of 2000Pa and0.002 m³/sec/m² at a differentialpressure of 50Pa. However, if lowerleakage rates are required as aspecial requirement, please consultour engineering department.
Ordering
Quantities, surface finish and otherspecial requirements to be statedseparately.
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Volume Controland ModulatingDampers
Typical Applications
These dampers have been designedto meet the requirements of theoffshore Oil and Gas and NuclearMarkets where corrosion resistanceand mechanical integrity are of primeimportance. They are used to controlairflow through ventilation systems,and are not intended for isolationpurposes.*
The following design features havebeen included:• Continuously welded construction• Opposed blade motion• Low airflow resistance• Low noise generation• Manual, pneumatic or
electric operation• Wide range of materials• Excellent corrosion resistance
CasingThe damper frame is formed into rigidchannel sections that are welded orriveted together. The construction isavailable in a range of materials andthicknesses. Typically: stainless steel(1.5 mm to 3.0 mm thick), grade 316Lor 304, pre-galvanised mild steelsheet or galvanised after manufacture(3.0 mm or 5.0 mm thick).
BladesThese are typically of stainless steelgrade 316L/304 or pre-galvanisedsteel. They are of double skin aerofoilsection and are riveted to continuoustubular spindles. The spindles rotatein acetal resin bearings and are linkedoutside the casing to provide opposedblade motion.
Adjusting MechanismModulating Damper: The bladelinkage is operated by a pneumatic orelectric actuator. The supply to theactuator is controlled by a positionerunit which is provided with an electric(4-20 mA, 0-10 V dc), or pneumatic (3-15 psi) control signal. The positionerunit can be supplied to provide afeedback signal at the HVAC controlpanel or management system.Electrical units can be suppliedsuitable for safe or hazardous areas.This system varies the airflow throughthe damper by adjusting the positionof the blades in relation to an externalparameter such as air temperature orroom pressurisation. Microswitchesfor remote indication of blades fullyopen and fully closed positions canalso be installed. The actuator,positioner unit and microswitches canbe housed within an enclosuremounted on one side of the dampercasing.
* If isolation of airflow is also arequirement, we recommend our isolatingdamper as detailed on Page 18 of thispublication.
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3Section
Type VCD Duct Width 600W
Material 316L Duct Height 400H
Case Thickness 3.0 Case Depth 200D
Type Wozair: Volume Control Dampers
Damper Types:PVCD = Pneumatic Volume Control DamperEVCD = Electric Volume Control Damper
Nominal Clear inside duct dimensionsDuct Size: ‘Quote’ (Width x Height)
Order Code Example:VCD/316L/3.0/600W/400H/200D
Volume Control Damper: Theblade linkage is manually operated bya robust adjusting handle whichmoves across a quadrant plate. Theplate is labelled to identify the openand closed positions. A locking deviceis provided to secure the handle in thedesired position which may beanywhere between open and closed.Volume control dampers are notdesigned to shut off the airflow in theclosed position.
OptionsThe following options can beincorporated if required: Oilimpregnated sintered bronze bearingsin place of acetal resin bushes.Reduced cost riveted/welded/sealedcasing construction. Sprung sideseals and top/bottom angle bladestops. Modifications to meet therequirements of specific clientspecifications eg. BNF Plc NF.
Ordering
Quantities, surface finish and otherspecial requirements to be statedseparately.
3Section
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Fan Inlet GuideVane Damper
Typical Applications
A range of high integrity dampers hasbeen designed to meet therequirements of the offshore oil andgas and nuclear markets wherecorrosion resistance, mechanicalintegrity and performance are primaryfactors. They are used to control andregulate airflow through mixed flow orcentrifugal fans. They are not intendedfor isolation purposes. The followingdesign features have been included:• Continuously welded construction• Parallel blade motion,
blades arranged radically• Manual, pneumatic or
electric operation• Excellent corrosion resistance
Description
Each damper comprises of threesections, the casing, the blades andthe adjusting mechanism.
CasingPrecision rolled with continuouslywelded seams and flanges availablein a range of materials andthicknesses typically: Stainless steel(2 mm to 5 mm thick), mild steelgalvanised after manufacture (3 mmor 5 mm thick). Note: The damperdepth is a function of the casediameter and therefore a variable.
BladesThese are single skin 3 mm marinegrade stainless steel and are securelybolted to stainless steel stubspindles. The stubs spindles rotate inoil impregnated, sintered, bronzebearings in the centre hub and casing,and are linked externally to provideparallel blade motion. Galvanisedmaterial option available.
Adjustment MechanismA robust external stainless steellinkage connects the blade stubspindles together and provides foreach blade segment to maintain anidentical angle through its travel fromfully open to close. The blade linkageis operated manually by a lever andlockable quadrant arrangement.
OptionsThe following drive options areavailable:
• Hand wheel and gearbox to providefine adjustment through the rangefrom fully open to closed.
• Pneumatic or electric actuator withthe supply controlled by a suitablepositioner to provide modulatingcontrol.
Mild Steel SheetGalvanised after Manufacture = GAM
Case Thickness: 2mm upwards
Nominal Clear inside duct dimensionsDuct Size: Ranging from 300 to 1000Ø
Order Code Example:IGVD/316L/2.0/300Ø
Ordering
Quantities, surface finish, drive optionand other special requirements to bestated separately.
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3Section
Non-Return/Pressure ReliefDamper
Typical Applications
A range of high integrity dampers hasbeen designed to meet therequirements of the offshore oil & gasand nuclear markets where corrosionresistance, mechanical integrity andperformance are primary factors. Theyare used to prevent backflow andrelieve pressure through ventilationduct systems. The following designfeatures have been included:• Continuously welded construction• Parallel blade motion• Low airflow resistance• Low noise generation• Excellent corrosion resistance
Description
CasingThe damper frame is formed into rigidchannel sections that are welded orriveted together from stainless steelgrade 304 or 316L, pre-galvanisedmild steel sheet or galvanised aftermanufacture (3.0 mm or 5.0 mmthick).
Angles with closed cell gaskets areprovided at the top and bottom in orderto achieve an effective seal betweenthe casing and the blades.
BladesThese are of stainless steel grade316L or 304, they are of double skinaerofoil section and are riveted tocontinuous tubular spindles. Thespindles rotate in oil impregnatedacetal resin bearings and are linkedexternally to provide parallel motion. Aneffective seal is achieved by strips ofclosed cell gasket along the bladeedges. Galvanised material optionavailable.
Blade LinkageThis is of stainless steel grade 316and is designed to prevent chatter orblade damage.
BalancingThis is achieved by either hangingweights from the holes provided in theblade linkage or by adjusting thetension of a spring balancingmechanism. This must be carried outon site after installation. Weight kitsand spring balancing mechanismsare optional and if required must bestated at the time of ordering.
Pressure Relief Damper: At fullairflow the position of the linkage issuch that the blades hang at between5° and 20° to the vertical.
Non-Return Dampers: At the“no flow” condition the blades hang at30° and 45° to the vertical.
OptionsThe following options can beincorporated if required.
Oilite bearings. Reduced cost riveted/welded/sealed casing construction.Weight kits or spring balancingmechanisms.Modifications to meet therequirements of specific clientspecifications eg BNF Plc NF.Low leakage style damper.
Nominal Clear inside duct dimensionsDuct Size: ‘Quote’ (Width x Height)
Order Code Example:NRD/316L/1.5/500W/300H/200D
Ordering
Quantities, surface finish and otherspecial requirements to be statedseparately.
3Section
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Butterfly Non-Return Damper
Typical Applications
A range of high integrity dampers hasbeen designed to meet therequirements of the nuclear industry,where low case leakage, corrosionresistance and mechanical integrityare of prime importance. They areused to prevent backflow whilstallowing airflow through mixed flow oraxial fan outlets. They are not intendedfor isolation purposes.The following design features havebeen included:• Gravity operation• Continuously welded construction• Dual blade pivotal around
CasingRolled casing manufactured from2mm minimum thick material, withwelded seam, length over flangesminimum 100mm. Welded flanges25 x 3mm thick drilled to standardnuclear specification pattern.Note: The damper depth is a functionof the case diameter and therefore avariable.
BladesA pair of semi-circular blades pivots onan individual shaft to form a 2mm thickcircular butterfly blade. Galvanisedmaterial option available.
Control and OperationBlades open under fan air pressureand close by gravity or backflowthrough the duct system
