ASME HST-3:2017 pdf download

ASME HST-3:2017 pdf download Performance Standard for Lever Hoists
SECTION 3-0.1 scoPE
(a) This Standard establishes performance require-ments for chain, wire rope, and web strap lever hoistsfor lifting. pulling, and tensioning applications (seeFigures 3-0.1-1,3-0.1-2,3-0.1-3, and 3-0.1-4).
(b) The specifications and information in this Standardapply 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
(-d) wire-rope-type lifting medium(2j 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 hand-ling high-voltage lines are not covered by this Standard.(d) This Standard is applicable to hoists manufacturedafter the date on which this standard is issued. ThisStandard 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(5y hoists used for the purpose of drawing both theload 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 asrequired by the Department of Defense (DoD).
The requirements of this Standard shall be appliedtogether with the requirements of ASME B30.21.Referto ASME B30.21 for requirements pertaining tomarking. construction, installation, inspection, testing.maintenance,and operation.
SECTION 3-0.2 DEFINITIONS
abnormal operating conditions: environmental conditionsthat are unfavorable, harmful, or detrimental to the opera-tion of a hoist, such as excessively high or low ambienttemperature, exposure to weather, corrosive fumes,dust-laden or moisture-laden atmospheres, and hazard-ous locations.
brake: a device for retarding and stopping motion of theload (see load-controlling mechanism).
hazardous (classified) locations: locations where fire orexplosion hazards may exist. Locations are classifiedaccording to the properties of the flammable vapors,liquids, gases,or combustible dust or fibers that maybe present, and the likelihood thata flammable or combus-tible concentration or quantity is present. Refer to ANSI/NFPA 70.
headroom (closed height): the distance between the saddleof the suspension hook and the saddle of the load hookwhen the load hook is in its fully retracted position (seeFigure 3-0.1-1).
idler sprocket: a freely rotating device that changes thedirection of the load chain, rope, or web strap.
lever hoist: a manually lever-operated device used to lift,lower, or pull a load and to apply or release tension.lever pull: the average force, lbf (kN), exerted by theoperator at the end of the operating lever (handle) tolift or pull rated load.
lift: the maximum distance through which the load hookcan travel (see Figure 3-0.1-1).
lifting devices: devices that are not normally reeved ontothe hoist rope, web strap, or chain, such as supplementaldevices used for handling or attaching to the load. Theweight of these devices is to be considered part of theload to be lifted.
lifting medium: the chain, wire rope, or web strap used bythe lever hoist to apply a force or support the load.load: the total superimposed force on the hoist load blockor load hook.
load block: the assembly of hook or shackle, swivel, bear-ings,sheaves,sprockets, pins,and frame suspended by theload chain, rope, or web strap.This shall include anyappurtenances reeved into the load chain, rope, or webstrap.
load chain: the load-bearing chain in the hoist.
roller chain: a series of alternately assembled rollerlinks and pin links in which pins articulate inside the bush-ings, and rollers are free to turn on the bushings.Pins andbushings are press-fit in their respective link plates.
welded-link chain: a chain consisting of interwoven linksformed and welded.
NOTE: Load-chain properties do not conform to those shown inASME B30.9.
load-controlling mechanism: a mechanism that functionsautomatically to hold and control the load. In each of thefollowing general types, a reciprocating force must beapplied to the hoist lever to lower the load:
friction-brake type: an automatic type of brake used forholding and controlling loads. This unidirectional devicerequires a force applied to the operating lever to lowertheload but does not impose additional lever pull when liftingthe load.
ratchet-and-pawl type: a load-controlling mechanismconsisting of interlocking pawl(s) and ratchet that actto hold the load by mechanical engagement.
load hook: the hook used to connect the load to the hoist.load suspension parts: the suspension hook, the chain, ropeor web strap, the sprocket(s), the structure or housing thatsupports the sprocket(s), and the load block.
normal operating conditions: conditions during which ahoist is performing functions within the scope of theoriginal design.