25 Jan AN AMERICAN NATIONAL STANDARD. ASME BTH-1– (Revision of ASME BTH-1–). Design of. Below-the-Hook. Lifting Devices. Buy ASME BTH 1: DESIGN OF BELOW-THE-HOOK LIFTING DEVICES from SAI Global. ASME BTH Design of Below the Hook Lifting Devices Reduced – Download as PDF File .pdf), Text File .txt) or read online.
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ASME-BTH – Free Download PDF
The Standards Committee that approved the code or standard was balanced to assure that individuals from competent and concerned interests have had an opportunity to participate.
However, the effects of stress concentrations are most important when determining fatigue life. Minimum Sizes of Fillet Welds. Design Category B will generally be appropriate for lifters that are to be used in severe environments.
The agreement of the computed BTH design factors with the prior practice was felt to validate the results. Fasteners shall be installed by an accepted method as determined by the lifting device manufacturer or a qualified person.
This stress increase shall be considered when evaluating fatigue. The length of the slot for a xsme weld shall not exceed 10 times the qsme of the weld. Suspended beams exhibit different behavior with respect to lateral torsional buckling Dux and Kitipornchai, The slip resistance of painted or coated surfaces varies greatly, depending on the type and thickness of coating.
Factors such as type and condition of gripping surfaces, environmental conditions, coefficients of friction, dynamic loads, and product temperature can affect the required support force and shall be considered during the design by a qualified person. The effective throat of a fillet weld shall be the shortest distance from the root to the face of the weld.
The selection of Design Category and Service Class shall be the responsibility of a qualified person representing the owner, purchaser, or user of the lifting device. They are intended to be used with cranes, hoists, and other lifting equipment. Stress Category Table The minimum center-to-center spacing in a longitudinal direction on any line shall be two times the length of the slot.
The effective weld area shall not exceed the cross-sectional area of the hole or slot. The SI units in the text have been directly softly converted from U.
Vth the bending moment at any point within an unbraced length is larger than that at both ends of this length, Cb shall be taken as adme [see eq. Groove welds loaded perpendicular to the axis of the weld shall be designed for tension or compression forces. The fatigue design requirements in section are generally based on the provisions of AWS D If the design factor of a commercial component is unknown, the maximum capacity of that component should be divided by the applicable value of Nd.
Thank you for interesting in our services. The slip resistance defined in this Standard is based on faying surfaces that are free of awme mill scale, paint, and other coatings.
Along with the forces produced by normal operation, mechanical components of lifting devices should be designed to resist the forces resulting from operating irregularities that are common in mechanical systems including jams, locked rotor torque, and overloads. Reversing contactors shall be interlocked. For circular tubes with compact walls as defined by Table Students Click Here Join Us!
The allowable bending stress for members with compact or noncompact sections as defined by Table Compliance with requirements and criteria that may be unique to specialized industries and environments is outside the scope of this Standard. ASME BTH-1— incorporated revisions throughout the Standard and the addition of a new mechanical design section for fluid power systems. The qualified person shall consider other factors i. The strength equations for the plates are empirical, based on research Duerr, N is the expected number of constant amplitude stress range cycles and is to be provided by the owner.
The minimum length of end returns shall be two times the weld size. This allowable stress results in a condition in which the bending stress will not exceed yield under the maximum loads defined in the load spectra upon which the design factors 11 based.
The use of other materials may require a different means of evaluating the fatigue life of the lifter. Lifting devices often are constructed with discontinuities or geometric stress concentrations such as pin and bolt holes, notches, inside corners, and shaft keyways that act as initiation 20111 for fatigue cracks.
The allowable single plane fracture strength beyond the pinhole Pb is Fp p 1. Approved revisions will be published periodically. Fatigue Stress Amplification Factors. The allowable stresses specified in these sections do not apply to peak stresses in regions of connections, provided gth requirements of section are satisfied. As with straight beam bending theory, the hth of the equations by which the bending stresses of a curved beam may be computed are based on the fundamental assumption that plane sections remain plane Young and Budynas, It shall indicate the presence of the minimum vacuum required for the rated load of the vacuum lifting device.
Loose chains or belts will experience accelerated wear and result in premature failure of the system. These references are cited for information only. It is not a strength limit. The allowable stress for members with compact sections provides a lower bound design factor of Nd with respect to the plastic moment. FSR shall be the smaller of the toe crack or root crack allowable stress range.