ASME HST-6–2020 pdf download.Performance Standard for Air Wire Rope Hoists.
SECTION 6-1.2: HOIST DUTY SERVICE CLASSIFICATION 6-1.2.1 General Considerations Service conditions have an importantinfluence on the performance ofwearingparts ofa hoist, such as gears, bearings, rope, sheaves, brake linings, load and lift limitdevices, wheels, and pneumatic components. Careful consideration ofthe hoist duty service classifications described in this Section will enable the user to evaluate the application and obtain a hoistdesigned for optimum performance and minimum maintenance. Ifdoubtexists regarding hoistselection, the hoist supplier should be consulted. Many factors enter into the selection of the proper hoist to perform a given function. Hoisting equipment consists of both mechanical and pneumatic components, and both must be considered when analyzing the service the hoist must perform. The factors that influence the performance of any hoist include the following: (a) LoadDistribution. Loaddistributionistheactualdistributionorproportionoffullandpartialloadstobehandledby the equipment, including lifting devices, and has an important effect on the life ofpower transmission components. For example, ball bearinglife varies accordingto the cube ofthe load. A2-ton (1 814.4-kg) hoistoperated ata mean effective load of 1 ton (907.2 kg) will have a ball bearing life of 8 times that of the same hoist used steadily at its rated load. (b) Operational Time. Operational time is the total running time of the hoist per hour or per work period. (c) Repetitive Long Lowering Operations. Such operations generate heat in control braking means. (d) Environmental Conditions. Examples include high or low ambient temperatures, dust, moisture, and corrosive fumes.
SECTION 6-1.4: SPEEDS — HOIST AND TROLLEY Hoisting equipmentis available over a wide range ofhoistand trolley speeds. Table 6-1.4-1 lists typical speed ranges. NOTE: Table 6-1.4-1 is to be used as a guide only and is not intended to restricteither the manufacturer or the buyer from offering or specifyingspeeds outside the ranges shown; norshoulditbe inferredthatspeeds above orbelowthe ranges shownare notcompatible with the required class of hoist.
SECTION 6-1.5: TROLLEYS Hoisttrolleysareavailableinplain,hand-chain-operated,andmotor-driventypes. Selectionofeachtypedependsupon the application. When a trolley is required for use with a hoist, the type and size ofsupport beam shall be specified to ensure that the trolley is suitable for the minimum radius and the contour of the beam.
6-1.5.1 Plain-Type Trolleys Aplain-type trolleyis recommendedwheretrolleymotionis infrequentorrelativelyshort. Due to the force requiredto manuallyoperate this type oftrolley, itis also recommendedthatthe use ofplaintrolleys be limitedto amaximumloadof 3 tons (2 727 kg), with the elevation of the beam not more than 20 ft (6 m) above the operator’s floor level.ASME HST-6 pdf download.