ASME HST-5:2020 pdf download

ASME HST-5:2020 pdf download.Performance Standard for Air Chain Hoists
(a) This Standard establishes performance requirements for air-powered chain hoists for vertical lifting service in- volvingmaterialhandlingoffreelysuspended(unguided) loadsusingloadchainoftherollerorweldedlinktypeswithone of the following types of suspension: (1) lug (2) hook or clevis (3) trolley (b) This Standard is applicable to hoists manufactured after the date on which this Standard is issued. It is not ap- plicable to (1) damaged or malfunctioning hoists (2) hoists that have been misused or abused (3) hoists that have been altered without authorization of the manufacturer or a qualified person (4) hoists used for lifting or supporting people, or (5) hoists used for the purpose of drawing both the load and the hoist up or down the hoist’s own load chain(s) Therequirements ofthis Standardshallbeappliedtogetherwiththerequirements ofASME B30.16. Pleasealso referto ASME B30.16 for requirements pertaining to marking, construction, and installation; inspection, testing, and mainte- nance; and operation.
abnormaloperating conditions: environmental conditions thatare unfavorable, harmful, or detrimental to the operation ofa hoist, such as excessively high or low temperatures, exposure to weather, corrosive fumes, dust-laden or moisture- laden atmospheres, and hazardous locations. ambient temperature: the temperature of the atmosphere surrounding the hoist. beam: an overhead standard structural or specially fabricated shape on which the trolley operates. brake: a device, other than a motor, used for retarding or stopping motion by means of friction or power. brake, holding: a friction brake for a hoist that is automatically applied and prevents motion when the air supply is interrupted. brake, mechanical load: an automatic type of friction brake used for controlling loads in a lowering direction. This unidirectional device requires torque from the motor to lower a load but does not impose additional load on the motor when lifting a load. This may also be used as a holding brake if designed as such by the manufacturer. braking, control: a method ofcontrolling speed by removingenergy from the moving body or by imparting energy in the opposite direction. braking, dynamic: a method of controlling speed by using the motor as a compressor. chain, hand: the chain provided to control movement of a hand chain-operated trolley. chain, load: the load-bearing chain in the hoist. chain, roller:aseriesofalternatelyassembledrollerlinksandpinlinksinwhichpinsarticulateinsidethebushingsandthe rollers are free to turn on the bushings. Pins and bushings are press-fit in their respective link plates. chain, welded link: a chain consisting of a series of interwoven links formed and welded. NOTE: Load chain properties do not conform to those shown in ASME B30.9. control: a device or group ofdevices that serves to govern in some predetermined manner the power delivered to the apparatus to which it is connected.
control, pendant: a valve system, connected to the hoist or trolley by hoses, thateither directly controls flow ofair to the motor or controls a pilot-operated valve system at the motor inlet. control, pull: cords or chains suspended from the hoist, by means ofwhich a valve system on the hoist can be operated. control, rod: a rigid rod suspended from the hoist, with which a valve system on the hoist can be operated. hazardous (classified) locations: locations where fire or explosion hazards may exist. Locations are classified depending on the properties ofthe flammable vapors, liquids, or gases, or combustible dusts or fibers that may be present, and the likelihood that a flammable or combustible concentration or quantity is present. Refer to ANSI/NFPA 70. headroom: headroom is measured with the load hookatits upperlimitoftravel and is the distance from the saddle ofthe load hook to the following locations (see Figure 5-0.2-1): (a) saddle of the top hook on hook-suspended hoists (b) centerline of the suspension holes on lug-suspended hoists (c) wheel treadline on trolley-suspended hoists hoist: a machinery unit that is used for lifting or lowering a freely suspended (unguided) load. hoist speed: the rate of motion that the load hook obtains while lifting rated load. hook suspended: suspension of the hoist from a trolley or rigid structure by means of a hook at top of hoist. idlersprocket: a freely rotating device that changes the direction ofthe load chain. This device is sometimes called idler wheel, idler sheave, pocket wheel, or chain wheel (see Figure 5-0.2-2).