ASME HST-1-2012 pdf download

ASME HST-1-2012 pdf download.Performance Standard for Electric Chain Hoists.
SECTION 1-0.1: SCOPE (a) This Standard establishes performance require- ments for electric chain hoists for vertical lifting service involving material handling of freely suspended (unguided) loads usingload chainoftherolleror welded link types with one ofthe 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 applicable to (1) damaged or malfunctioning hoists (2) hoists that have been misused or abused (3) hoists that have been altered without authoriza- tion of the manufacturer or a qualified person (4) hoists used for lifting or supporting people (5) hoists used for the purpose of drawing both the load and the hoist up or down the hoist’s own load chain(s) (6) hoists used for marine and other applications as required by the Department of Defense (DOD) The requirements of this Standard shall be applied together with the requirements of ASME B30.16. Please also refer to ASME B30.16 for requirements pertaining to marking, construction, and installation; inspection, testing, and maintenance; and operation. SECTION 1-0.2: DEFINITIONS abnormal operating conditions: environmental conditions thatare unfavorable, harmful, or detrimental to the oper- ation ofa hoist, such as excessively high or low tempera- ture, 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 fabri- cated shape, on which the trolley operates. brake: a device, other than a motor, used for retarding or stopping the hoist or trolley motion by friction or power means. 1 brake, holding: a friction brake for a hoist that is automati- cally applied and prevents motion when power is off. brake, mechanical load: an automatic type of brake used for controlling loads in a lowering direction. This unidi- rectional device requires torque from the motor to lower a load but does not impose additional load on the motor when lifting a load. chain, load: the load-bearing chain in the hoist. chain, roller: a series of alternately assembled roller links and pin links in which pins articulate inside the bush- ings, and the 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 inter- woven links formed and welded. NOTE: Load chain properties do not conform to those shown in ASME B30.9 or ASME B29.1. contactor: an electromechanical device for opening and closing an electric power circuit. control actuator: a manual means at the operating station by which hoist controls are energized. control enclosure: the housing containing the electrical control components. controlledbrakingmeans: a method ofcontrollingspeed by removing energy 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 generator, with the energy being dissipated by resistance. braking, mechanical: a method of controlling or reduc- ing speed by friction. braking, regenerative: a method of controlling speed in which the electrical energy generated by the motor is fed back into the power system. cushioned start: an electrical or mechanical method for reducing the rate of acceleration of trolley motion. hazardous (classified) locations: locations where fire or explosion hazards may exist. Locations are classified depending on the properties of the flammable vapors,liquids or gases, or combustible dusts or fibers that maybe present, and the likelihood that a flammable or combustible concentration or quantity is present. Refer to ANSI/NFPA 70. class 1: locations in which flammable gases or vapors are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures. class 2: locations that are hazardous because of the presence of combustible dust. class 3: locations that are hazardous because of the presence ofeasily ignitable fibers or flyings, butinwhich such fibers or flyings are not likely to be in suspension in the air in quantities sufficient to produce ignitable mixtures. headroom: headroom is measured with the load hook at its upper limit of travel and is the distance from the saddle of the load hook to the following locations (see Fig. 1-0.2-1): (a) saddle of the top hook on hook suspended hoists (b) centerline of the suspension holes on lug sus- pended hoists (c) wheel treadline on trolley suspended hoists hoist: a suspended 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. 2 hooksuspended: suspension ofhoist from a trolley or rigid structure by means of a hook at top of hoist. idler sprocket: a freely rotating device that changes the direction of the load chain. This device is sometimes called idler wheel, idler sheave, pocket wheel, or chain wheel (see Fig. 1-0.2-2). lift: the maximum vertical distance through which the load hook can travel, and is the total hook movement between its upper limit of travel and its lower limit of travel (see Fig. 1-0.2-1). lifting devices, below-the-hook: devices that are not nor- mallyreeved onto the hoistchains suchas hook-onbuck- ets, magnets, grabs, and other supplemental devices used for handling certain types of loads.