ASME HST-4:2021 pdf download

ASME HST-4:2021 pdf download.Performance Standard for Overhead Electric Wire Rope Hoists
abnormaloperating conditions: environmental conditions thatare unfavorable, harmful, or detrimental to the operation ofa hoist, such as excessively high or low ambient 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. base ordeckmounted: a type ofmounting where the hoist is mounted to the top side ofa horizontal supporting surface. beam: an overhead standard structural or specially fabricated shape on which the trolley operates. block, load: the assembly ofhook or shackle, swivel, bearing, pins, sheaves, and frame suspended by the rope. This shall include all appurtenances reeved into the hoisting rope. brake: a device, other than a motor, used for retarding or stopping motion by friction or power means. brake, holding: a friction brake for a hoist that is automatically applied and prevents motion when power is off. 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. A mechanical load brake 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, countertorque (plugging): a method of controlling speed by applying a variable motor torque in the direction opposite to the direction that the motor is rotating as it is being overhauled by the load.
braking, dynamic: a method ofcontrolling speed by using the motor as a generator, with the energy being dissipated by resistance. braking, eddy current: a method of controlling or reducing speed by means of an electrical induction load brake. braking, mechanical: a method of controlling or reducing speed by friction. braking, regenerative:amethodofcontrollingspeedinwhichtheelectricalenergygeneratedbythe motoris fedbackinto the power system. ceiling mounted: a type ofhoistmountingwhere the hoistis mounted to the underside ofa horizontal supportingsurface. chain, hand: the chain provided to control movement of a hand-chain-operated trolley. contactor: an electromechanical device for opening and closing an electric power circuit. control: a device or group of devices that serves to govern in some predetermined manner the power delivered to the apparatus to which it is connected. control actuator: a manual means at the operating station by which hoist or trolley controls are energized. control enclosure: the housing containing the electrical control components. cushioned start: an electrical or mechanical method for reducing the rate of acceleration of trolley motion. drum: the cylindrical member around which the rope is wound for lifting and lowering the load. 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).
hoist: 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 a rated load. hook suspended: suspension of the hoist from a trolley or rigid structure by means of a hook(s) at top of hoist. lateralhooktravel: the lateral movementofthe load hookbetween its position atthe upperlimitoftravel and its position at the lower limit of travel. lift: the maximum vertical distance through which the load hook can travel; it is the total hook movement between its upper limit of travel and its position at the lower limit of travel (see Figure 4-0.2-1). lifting devices, below-the-hook: devices that are not normally reeved onto the hoist ropes, such as hook-on-buckets, magnets, grabs, and other supplemental devices used for handling certain types of loads. The weight of these devices is to be considered part of the load to be lifted. limitdevice: a device thatlimits equipmentmotion or takes control ofparticular functions withoutaction ofthe operator when a limiting condition is reached. load hook: the hook used to connect the load to the hoist. load, rated: the maximum load for which a hoist or trolley is designated by the manufacturer or qualified person. load, working: the external load applied to the hoist, includingthe weightofload attachingequipmentsuch as shackles or slings. loadsuspension parts:themeansofsuspension(trolley,hook,orlug),thestructure,orhousingthatsupportsthedrum,the rope, the sheaves, and the load block. lug suspended: suspension ofthe hoist from a trolley(s) or permanent structure by means ofbolt(s) or pin(s) through a rigid- or swivel-type lug(s).