ASME BTH-1-2008 pdf free download.Design of Below-the- Hook Lifting Devices.
1-3 NEW AND EXISTING DEVICES
The effective date of this Standard shall be one year after its date of issuance. lifting devices manufactured after the effective date shall conform to the requirements of this Standard.
When a lifter is being modified, its design shall be reviewed relative to this Standard, and the need to meet this Standard shall be evaluated by the manufacturer or a qualified person.
Commentary: It is not the intent of this Standard to require retrofitting of existing lifting devices.
1-4 GENERAL REQUIREMENTS
1-4.1 Design Responsibility
Lifting devices shall be designed by, or under the direct supervision of, a qualified person.
Commentary: Although always implied, this provision now explicitly states that the design of below-the- hook lifting devices is the responsibility of a qualified person. This requirement has been established in recognition of the impact that the performance of a lifting device has on workplace safety, the complexity of the design process, and the level of knowledge and training required to competently design lifting devices.
1-4.2 Units of Measure
A dual unit format is used. Values are given in U.S. Customary units as the primary units followed by the International System of Units (SI) in parentheses as the secondary units. The values stated in U.S. Customary units are to be regarded as the standard. The Si units in the text have been directly (softly) converted from U.S. Customary units.
Commentary: The requirements of this Standard are presented wherever possible in a manner that is dimensionally independent, thus allowing application of these requirements using either U.S. Customary units
1-5 DEFINITIONS
The paragraph given after the definition of a term refers to the paragraph where the term is first used.
Commentary: This section presents a list of definitions applicable to the design of below-the-hook lifting devices. Definitions from the ASME Safety Codes and Standards Lexicon and other engineering references are used wherever possible. The defined terms are divided into general terms (para. 1-5.1) that are considered broadly applicable to the subject matter and into groups of terms that are specific to each chapter of the Standard.
1-5.1 Definitions — General
ambient temperature: the temperature of the atmosphere surrounding the lifting device (para. 1-4.7).
below-the-hook lifting device (lifting device, lifter): a device, other than slings, hooks, rigging hardware, and lifting attachments, used for attaching loads to a hoist (section 1-1).
cycle, load: one sequence of two load reversals that define a range between maximum and minimum load (para. 1-5.1).
design: the activity in which a qualified person creates devices, machines, structures, or processes to satisfy a human need (section 1-1).
design factor: the ratio of the limit state stress(es) of an element to the permissible internal stress(es) created by the external force(s) that act upon the element (para. 1-6.1).
fatiçue: the process of progressive localized permanent material damage that may result in cracks or complete fracture after a sufficient number of load cycles (para. 1-5.2).
fatigue life: the number of load cycles of a specific type and magnitude that a member sustains before failure (para. 1-4.5).
hoist: a machinery unit that is used for lifting and lowering (para. 1-5.1).
lifting attachment: a load supporting device attached to the object being lifted, such as lifting lugs, padeyes, trunnions, and similar appurtenances (para. 1-5.1).
load(s), applied: external force(s) acting on a structural member or machine element due to the rated load, dead load, and other forces created by the operation and geometry of the lifting device (para. 1-5.2).
load, dead: the weights of the parts of the lifting device (para. 1-5.1).
load, rated: the maximum load for which the lifting device is designated by the manufacturer (para. 1-4.3).