ASME HST-3–2022 pdf download
ASME HST-3–2022 pdf download.Performance Standard for Lever Hoists.
rollerchain: a series ofalternatelyassembled rollerlinks and pin links in which pins articulate inside the bushings and rollers are free to turn on the bushings. Pins and bushings are press-fit in their respective link plates. welded-link chain: a chain consisting of interwoven links formed and welded. NOTE: Load-chain properties do not conform to those shown in ASME B30.9. load-controlling mechanism: a mechanism that functions automatically to hold and control the load. In each of the following general types, a reciprocating force must be applied to the hoist lever to lower the load: friction-brake type: an automatic type of brake used for holding and controlling loads. This unidirectional device requires a force applied to the operating lever to lower the load but does not impose additional lever pull when lifting the load. ratchet-and-pawltype: a load-controllingmechanism consistingofinterlockingpawl(s) and ratchetthatactto hold the load by mechanical engagement. load hook: the hook used to connect the load to the hoist. loadsuspension parts:themeansofsuspension(trolley,hook,orlug),thestructure,orhousingthatsupportsthedrum,the rope, the sheaves, and the load block. may: used to denote permission, neither a requirement nor a recommendation. normal operating conditions: conditions during which a hoist is performing functions within the scope of the original design. operating lever: the lever or handle provided to operate the hoist. overload: any load greater than the rated load. pawl: a device that engages the ratchet to prevent rotation. qualifiedperson: a person who, bypossession ofa recognized degree in an applicable field or a certificate ofprofessional standing or by extensive knowledge, training, and experience, has successfully demonstrated the ability to solve or resolve problems relating to the subject matter and work. ratchet: a toothed member that engages with a pawl. rated load (capacity): the maximum load designated by the manufacturer for which a hoist is designed and built.
SECTION 3-1.1: GENERAL All equipment selected in accordance with this Standard shall perform satisfactorily when used in accordance with ASME B30.21, Chapters 21-2 through 21-4 and within the rated load. All equipment shall provide operating lever pull, lift, and headroom in accordance with the manufacturer’s specifica- tions or the specifications agreed upon by the manufacturer and user. SECTION 3-1.2: ð22Þ APPLICATION Leverhoistsshallbesuitableforliftingorloweringandpullingortensioningloads withintheirratedload. Theyshallbe capable ofuse in pulling or tensioning applications atany angle, provided the load block, lifting medium, and hoist body are not restricted from forming a straight line with the direction of loading. The hoists covered bythis Standard are intended forindustrial use in ambienttemperatures from 0°F to 130°F (−18°C to 54°C) and shouldperformsatisfactorilywhen applied andoperatedinthe mannerdescribedin this Standard. The user should consult with the manufacturer for lever hoists to be used in hazardous (classified) locations or under abnormal operating conditions. Refer to ASME B30.21 for construction, installation, inspection, testing, operation, and mainte- nance. Because ofvarying environmental conditions, loading, and usage, the hoist service life is interrelated to the type and frequency of maintenance performed on the unit. Equipment covered by this Standard should be inspected and main- tained according to ASME B30.21, Chapter 21-4. Nonmandatory Appendix B provides guidance for both the manufacturer and the end user in configuring a hoist to make it suitable for use in a potentially explosive environment.
SECTION 3-1.3: OPERATING CHARACTERISTICS Lever hoists shall be constructed to provide the following operating characteristics: (a) The hoistshall lift, lower, orpull a load, and applyorrelease tension in controlled increments whena manual force is applied to the operating lever (handle). (b) The hoist shall lift or pull the rated load when an appropriate lever pull is exerted by one operator (see Section 3-1.4). (c) Thehoistshallbeequippedwithamechanism(frictionbrakeorratchet-and-pawl) thatshallholdandcontrolloads within the rated load when the hoist is operated in either direction. (d) The hoist shall be equipped with accessible operating controls. (e) The hoistshould have a free-wheelingcapabilitythatwill allowthe operatorto adjustthe load hookposition when the unit is not under load. SECTION 3-1.4: PERFORMANCE CHARACTERISTICS See Tables 3-1.4-1 through 3-1.4-4 for generally available lever hoist capacities and typical performance character- istics. SECTION 3-1.5: ð22Þ OVERLOAD LIMITING DEVICE An overload limiting device, when furnished, shall permit operation of the hoist within its rated load and limit the amountofoverload thatcan be lifted orapplied bya properlymaintained leverhoistundernormal operatingconditions. The overload device may allow the lifting or applying of an overload but shall prevent the lifting or applying of an overload that could cause damage to the lever hoist. ASME HST-3-2022
