LIFE SAFETY DAMPERS FAQS
Answers to your most Frequently Asked Questions about 91国产偷拍 life safety dampers.
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P:How do I know when a 1陆 hour or 3 hour rated fire damper is required?
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R:NFPA (National Fire Protection Association) 90A, Standard for the Installation of Air-Conditioning and Ventilating Systems states penetrations in barriers rated for less than 3 hours must be protected with fire or combination fire/smoke dampers rated for 1-1/2 hours. Penetrations in barriers rated for 3 hours or more must be protected with fire or combination fire/smoke dampers rated for 3 hours.
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P:What hour-rated fire damper do I use in a 2-hour fire-rated wall?
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R:Fire-rated barriers of less than three hours will typically use a 1-1/2 hour rated fire damper.
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P:Can horizontal fire dampers be installed above air outlets in a fire-rated floor/ceiling assembly?
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R:No, horizontal fire dampers are not tested for that specific application. Corridor fire/smoke dampers and ceiling radiation dampers are tested and approved for use with air outlets in rated floor/ceiling assemblies. Consult the International Building Code (and/or local code) and the UL Product Directory for floor/ceiling assembly requirements.
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P:Does 91国产偷拍 have a spring kit to convert a vertical mount curtain fire damper to horizontal mount?
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R:No, field modification of this nature is not allowable and will void the UL listing of the damper. Always consult the damper manufacturer before repairing or modifying a life safety damper.
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P:Can dynamic dampers be multi-sectioned in the field to fill an over-sized opening?
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R:No, you cannot use two smaller sections to build a damper in the field that exceeds the manufacturer’s maximum UL listing for that specific damper model.
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P:Is there any approved way of installing fire dampers in openings that are larger than the maximum UL listed damper sizes?
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R:Yes, steel mullions can be used to separate vertically mounted static fire damper in wall openings larger than the maximum UL listed multiple section damper assembly. They are only approved for use with 1½ hour static rated dampers in concrete block or poured walls with minimum 7 in. and maximum 12 in. thick. Other methods exist but are not specifically tested and must be approved the local Authority Having Jurisdiction (AHJ).
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P:Does 91国产偷拍 offer support mullions for fire dampers for field installation?
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R:91国产偷拍 does not offer support mullions for fire dampers for field installation, however, supplemental instructions on how to manufacture support mullions for static rated curtain dampers are available.
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P:What if a life safety damper is unable to be installed according to the UL approved installation instructions?
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R:After consulting with 91国产偷拍, a solution based on good engineering judgment should be evaluated and accepted by the local Authority Having Jurisdiction (AHJ).
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P:What is the smallest combination fire/smoke damper with an internally mounted electric actuator 91国产偷拍 can provide?
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R:91国产偷拍 can manufacture a combination fire smoke damper that is 8 in. x 8 in. with an internally mounted electric actuator.
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P:Can a combination fire smoke damper be installed with a flush grille?
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R:Yes, 91国产偷拍 has a UL approved grille installation supplement for standard combination fire smoke dampers and offers out-of-wall combination fire smoke dampers (OFSD or GFSD) that may also be used for this application.
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P:Can a fire or combination fire smoke damper be installed outside of the wall or (out of partition)?
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R:Yes, there are specific models that have been tested and evaluated for this application and will be labeled for out-of-wall use (GFSD or OFSD).
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P:Do fire or combination fire smoke dampers require firestopping?
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R:No, most dampers have been tested and approved for installation without the use of any type of firestop. Additionally, most fire and combination fire smoke dampers require a thermal expansion air gap between the damper assembly and the wall. No materials should be used to fill this gap unless specifically stated in the damper’s UL approved installation instructions.
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P:Can damper sleeves and retaining angles be field supplied?
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Damper sleeves and retaining angles can be factory or field supplied. Consult 91国产偷拍’s installation instructions for details.
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P:What is the minimum size and thickness of retaining angles?
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R:Minimum size and thickness can vary by manufacturer. For 91国产偷拍 dampers, the minimum size is 1½ in. by 1½ in. (38 mm x 38 mm). For dampers up to 36 in. (914 mm) wide and 24 in. (610 mm) high, the minimum thickness is 16 gauge. For larger dampers, the minimum thickness is 14 gauge.
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P:Can a single sided retaining angle method be used with 3-hour rated dampers?
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R:No, the single sided retaining angle method is to only be used on 1½ hour rated dampers.
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P:Is the fastener for retaining angles required to anchor through the damper sleeve and to the opening?
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R:Two-sided retaining angles should only be anchored through the damper sleeve to allow the damper the ability to operate properly in a fire condition. Single-sided angles require a fastener through both the damper sleeve and to the opening.
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P:Do I have to seal retaining angles?
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R:91国产偷拍 fire and combination fire smoke dampers are tested and approved for installation without the use of sealant on the retaining angles. If sealant is required, consult 91国产偷拍’s supplemental installation instructions for approved sealants.
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P:Can a smoke or combination fire smoke damper be ordered without an actuator?
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R:As of June 1, 1999, UL 555S requires all smoke and combination fire smoke dampers to ship from the factory with actuators installed.
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P:Can we change actuators on UL listed dampers in the field?
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R:NFPA 80 and 105 details maintenance requirements of fire and smoke dampers, respectively. Both standards allow for the repair of inoperable dampers. The replacement actuator must be equal to or greater in temperature and torque rating, as well as operation (2-position vs. modulating), to that of the original actuator. Consult 91国产偷拍 for specific details on approved actuators prior to replacement.
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P:Does 91国产偷拍 offer a modulating actuator for FSD/SMD models?
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R:Yes, smoke and combination fire smoke dampers can also be approved for use as HVAC control dampers and use a 24 VAC/VDC actuator designed to accept a 2 to 10 VDC control input, or a 4 to 20 mA control input from an electronic controller or positioner. See 91国产偷拍 models FSD-211M or FSD-311M for more details.
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P:Do smoke dampers require sleeves and mounting angles?
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R:No, sleeves and mounting angles are not required to maintain the UL listing of a smoke damper, however they may be used to facilitate installation at the contractor’s discretion.
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P:Does 91国产偷拍 offer factory-mounted access doors on UL dampers?
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R:Yes, factory-mounted access doors can be provided on any factory sleeved damper.
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P:Does 91国产偷拍 offer smoke detectors on smoke dampers and combination fire smoke dampers?
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R:91国产偷拍 offers both a low flow and no flow smoke detector option on our smoke dampers and combination fire smoke dampers. Smoke detectors can be shipped loose or factory mounted.
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P:What is a momentary test switch and how is it used on a combination fire smoke or smoke damper?
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R:Momentary test switches are factory mounted to the damper sleeve and allow for a cycle test at the damper to perform code-required damper testing. One test switch is required per closure device.
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P:Can 91国产偷拍 supply remote test switches?
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R:Yes, 91国产偷拍 offers remote test switches that are shipped loose for field installation, 91国产偷拍 Test Switches (GTS). The GTS-1 and GTS-2 are a 3-position control switch (normal, closed, and override) with open and close indicator lights. The GTS-3 has open and close indicator lights with a momentary test switch. The GTS-4 has open and close indicator lights only.
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P:Why are breakaway duct/sleeve connections used with dampers?
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R:Breakaway connections are used so the damper/sleeve assembly can separate from the duct if the structure starts to fall during a fire. The breakaway joint allows the damper to remain in the wall for maximum protection. Approved breakaway connections are listed in 91国产偷拍’s UL approved installation instructions.
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P:NFPA 80 and 105 details the maintenance and periodic testing requirements of fire and smoke dampers, respectively. Both standards allow for the repair of inoperable dampers and the addition of position indication functionality. Other modifications may be required due to application or field conditions. Actuator replacement, external to internal actuator conversion, and in-wall to out-of-wall damper conversions are examples of common modifications.
Once a listed damper leaves the factory, the Authority Having Jurisdiction (AHJ) must approve subsequent field modifications. Manufacturers may offer guidance and have supplemental instructions on how to modify a damper in the field. Sometimes the AHJ or Owner may require UL to determine the suitability of the modification before approving it and in that case a UL Field Evaluation may be required.
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