ASME BTH-1:2005 pdf download Design of Below-the-Hook Lifting Devices
1-1 PURPOSE
This Standard sets forth design criteria forASME B30.20 below-the-hook lifting devices.ThisStandard serves as a guide to designers, manufacturerspurchasers, and users of below-the-hook lifting devices
Commentary:This Standard has been developed inresponse to the need to provide clarification of theintent of ASME B30.20 with respect to the structuradesign of below-the-hook lifting devices. Since the original publication of ASME B30.20in 1986,users haverequested interpretations of the construction (structuraldesign) requirements stated therein. The level of detailrequired to provide adequate answers to the questionssubmitted extends beyond that which can be coveredby interpretations of a B30 safety standard.
1-2 SCOPE
This Standard provides minimum structural ancmechanical design and electrical component selectioncriteria for ASE B3020 below-the-hook lifting devicesThe provisions in this Standard apply to the desigror modification of below-the-hook lifting devices. Compliance with requirements and criteria that may beunique to specialized industries and environments isoutside of the scope of this Standard.Lifting devices designed to this Standard shall complywith ASME B30.20，Below-the-Hook Lifting DevicesASME B30.20 includes provisions that apply to themarking,construction, installation, inspection, testingmaintenance,and operation of below-the-hook liftingdevices.
Commentary: ASME BTH-1 addresses only designrequirements. As such, this Standard should be used inconjunction with ASME B30.20, which addresses safetyrequirements. ASME BTH-1 does not replaceASME B30.20.The design criteria set forth are minimumrequirements that may be increased at the discretion ofthe lifting device manufacturer or a qualified person.
1-3 NEW AND EXISTING DEVICES
The effective date of this Standard shall be one yearafter its date of issuance. Lifting devices manufacturedafter the effective date shall conform to the requirementsof this Standard.
When a lifter is being modified, its design shall bereviewed relative to this Standard, and the need to meetthis Standard shall be evaluated by the manufacturer ora qualified person.
Commentary: lt is not the intent of this Standard torequire retrofitting of existing lifting devices.
GENERAL REQUIREMENTS1-4
1-4.1 Design Responsibility
Lifting devices shall be designed by, or under thedirect supervision of, a qualified person.
Commentary:Although always implied, this provision now explicitly states that the design of below-thehook lifting devices is the responsibility of a qualifiedperson.This requirement has been established in recognition of the impact that the performance of a liftingdevice has on workplace safety, the complexity of thedesign process, and the level of knowledge and trainingrequired to competently design lifting devices.
1-4.2 Units of Measure
A dual unit format is used. Values are given in USCustomary units as the primary units followed by theInternational System of Units (SI) in parentheses as thesecondary units. The values stated in US. Customarvunits are to be regarded as the standard. The SI unitsin the text have been directly (softly) converted fromUS.Customary units.
Commentary: The requirements of this Standard arepresented wherever possible in a manner that is dimensionally independent, thus allowing application of theserequirements using either U.S. Customary units (USCU)