ASME BTH-1:2005 pdf free download

ASME BTH-1:2005 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 alter its date of issuance. Lilting 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: ft 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 dimen. sionally independent, thus allowing application of these requirements using either U.S. Customary units (USCU)
Commentary: Ambient operating temperature limits are intended only to be a guideline. The component temperature of each part of the lifter must be considered when the device is operating in an environment outside the limits defined in para. 1-4.7. The effects of dust, moisture, and corrosive atmospheric substances on the integrity and performance of a lifter cannot be specifically defined. These design considerations must be evaluated and accounted for by the lifting device manufacturer or qualified person.
2-2 DESIGN CATEGORY
The design categories defined in paras. 2-2.1 and 2-2.2 provide for different design factors that establish the stress limits to be used in the design. The design factors are given in para. 3-1.3.
Lifters shall be designed to Design Category B, unless a qualified person determines that Design Category A is appropriate.
Commentary: When selecting a Design Category, consideration shall be given to all operations that will affect the lifting device design. The discussions of the Design Categories below and in Commentary for para. 3-1.3 refer to considerations given to unintended overloads in development of the design factors. These comments are in no way to be interpreted as permitting a lifting device to be used above its rated load under any circumstances other than for load testing in accordance with ASME B30.20 or other applicable safety standards or regulations.
2-2.1 Design Category A
(a) Design Category A should be designated when the magnitude and variation of loads applied to the lifter arc predictable, where the loading and environmental conditions are accurately defined or not severe.
(&) Design Category A lifting devices shall be limited to Service Class 0.
(c) The nominal design factor for Design Category A shall be in accordance with para. 3-1.3.
Commentary: The design factor specified in Chapter 3 for Design Category A lifters is based on presumptions of rare and only minor unintended overloading, mild impact loads during routine use, and a