ASME HST-3 pdf download.Performance Standard for Lever Hoists.
(a) ASME HST-3 establishes performance requirements for chain, wire ropc, and web strap lever hoists for lifting, pulling, and tensioning applications (see Figures 3-0.1-1, 3-0.1-2, 3-0.1-3, and 3-0.1-4).
(b) The specifications and information in this Standard apply to lever hoists of the following types:
(1) ratchet-and-pawl operation with
(-a) roller-type load chain lifting medium
(-b) welded-link-type load chain lifting medium
(-c) web-strap-type lifting medium
(4) wire-rope-type lifting medium (2) frictIon-brake operation with
(-a) roller-type load chain
(-b) welded-link-type load chain
(-c) web-strap-type lifting medium
(-d) wire-rope-type lifting medium
(c) Specially insulated lever hoists designed for handling high-voltage lines are not covered by this Standard.
(d) This Standard is applicable to hoists manufactured after the date on which this Standard is issued. This Standard is not applicable 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
(5) hoists used for the purpose of drawing both the load and hoist up or down the hoist’s own load chain(s). wire rope(s), or web strap(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 B30.21. Refer to ASME B30,21 for requirements pertaining to marking, construction, installation, inspection, testing, maintenance, and operation.
SECTION 3-0.2 DEFINITIONS
abnormal operating conditions: environmental conditions that are unfavorable, harmful, or detrimental to the operation of a hoist, such as excessively high or low ambient temperature, exposure to weather, corrosive fumes, dust-laden or moisture-laden atmospheres, and hazardous locations.
A-2.7 Interchangeability
In no case shall parts be physically interchangeable or reversible unless such parts are also interchangeable or reversible with regard to function, performance, and strength. Component parts for the same type of hoists from the same manufacturer shall be interchangeable to the greatest extent possible.
A-3 MECHANICAL REQUIREMENTS
A-3.i Design Stress
The maximum combined stress in component parts shall not exceed 35% of the tensile yield strength of the material for hoist operation at rated load. The maximum combined stress in component parts shall not exceed 70% of the tensile yield strength of the material. For all classes of hoists at rated load, the safety factor for load-bearing parts shall not be less than 3. based on the yield strength of the materials used; ora minimum safety factor of 5, based on the ultimate strength, whichever provides the lowest design stress. For hoists requiring repair parts, all wear parts shall be readily accessible for replacement. Equivalent spares for the same class and type hoists shall be interchangeable.
When specified Isee A-5.1 (e)I, the hoist shall withstand grade A high-impact shock. Unloaded hoists, when stowed on a pad, shall withstand highimpact shock in accordance with grade A of MIL-S-901, without permanent deformation or degradation of any operating functions.
A-3.2 Load Chain
As specified in A-5.1(fj, load chain shall be link- or roller-type. The load chain shall have a safety factor of 5 for the rated load of the hoist, based on the ultimate strength of the material. The load chain shall be selected from any of the AISI grade designations of ASTM A304 or ASTM A322. The load chain shall be easily replaceable.
A-3.2.1 Load Chain Container. When specified Isee A- 5.1(g)], hoists shall be equipped with a load chain container of durable construction to store the slack load chain. The load chain container shall have sufficient volume to contain the slack load chain and shall be located to prevent interference with the hoist operation.
A-3.2.2 Load Chain Sprocket and Shaft. The load chain sprocket may he integral with or rigidly connected to the load chain shaft. Welding of the load chain sprocket to the shaft is not permitted.
ASME HST-3 pdf download
