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ASME B31Ea-2010 pdf download

ASME B31Ea-2010 pdf download.Addenda to ASME B31E-2008 Standard for the Seismic Design and Retrofit of Above-Ground Piping Systems.
1 PURPOSE This Standard establishes a method for the seismic design of above-ground piping systems in the scope of the ASME B31 Code for Pressure Piping. 1.1 Scope This Standard applies to above-ground, metallic pip- ing systems in the scope of the ASME B31 Code for Pressure Piping (B31.1, B31.3, B31.4, B31.5, B31.8, B31.9, B31.11). The requirements described in this Standard are valid when the piping system complies with the materials, design, fabrication, examination, testing, and inspection requirements of the applicable ASME B31 Code section. 1.2 Terms and Definitions active components: components that must perform an active function, involving moving parts or controls dur- ingorfollowingthe earthquake (e.g., valves, valve actua- tors, pumps, compressors, and fans that must operate during or following the design earthquake). axial seismic restraint: seismic restraint that acts along the pipe axis. critical piping: piping system that must remain leak tight or operable (see definitions) during or following the earthquake. design earthquake: the level of earthquake for which the piping system is to be designed for to perform a seismic function (position retention, leak tightness, or operability). ductile piping system: in the context of this Standard for seismic qualification, ductile piping system refers to a pipingsystemwhere the piping, fitting,and components are made of material with a minimum elongation at rupture of 15% at the temperature concurrent with the seismic load. free-field seismic input: the ground seismic input at the facility location. in-structure seismic input: the seismic excitation within a building or structure, at the elevation of the piping sys- tem attachments to the building or structure. lateral seismic restraints: seismic restraints that act in a direction perpendicular to the pipe axis.
leak tightness: the ability of a piping system to prevent leakage to the environment during or following the earthquake. noncritical piping: piping system other than critical pip- ing that nevertheless must meet the requirements for position retention. operability: the ability of a piping system to deliver, con- trol (throttle), or shut off flow during or after the design earthquake. position retention: the ability of a piping system not to fall or collapse in case of design earthquake. seismic design: the activities necessary to demonstrate that a piping system can perform its intended function (position retention, leak tightness, operability, or a com- bination) in case of design earthquake. seismic function: a function to be specified by the engi- neering design either as position retention, leak tight- ness, or operability. seismic interactions: spatial or system interactions with other structures, systems, or components that may affect the function of the piping system. seismic response spectra: a plot or table of accelerations, velocities, or displacements versus frequencies or periods. seismic restraint: a device intended to limit seismic move- ment of the piping system. seismic retrofit: the activities involved in evaluating the seismic adequacy ofan existing piping system and iden- tifying the changes or upgrades required for the piping system to perform its seismic function. seismic static coefficient: acceleration or force statically applied to the piping system to simulate the effect of the earthquake.
2 MATERIALS 2.1 Applicability This Standard applies to metallic ductile piping sys- tems, listed in the applicable ASME B31 Code section. 2.2 Retrofit The seismic retrofit of existing piping systems shall take into account the condition of the system and its restraints. As part of the seismic retrofit, the piping sys- tem shall be inspected to identify defects in the piping or its supports and current and anticipated degradation that could prevent the system from performing its seis- mic function. 3 DESIGN 3.1 Seismic Loading The seismic loading to be applied may be in the form of horizontal and vertical seismic static coefficients, or horizontal and vertical seismic response spectra. The seismic inputis to be specified by the engineering design in accordance with the applicable standard (such as ASCE 7) or site-specific seismic loading (para. 1.3). When the seismic design force is computed based on para. 13.3.1 of ASCE 7, or a similar standard, the parameter a p shall be 2.5 and the parameter R p shall not exceed 3.5 when applying the stress limits of para. 3.4. When the alternative design methods of para. 3.5 are used, the derivation of seismic inputs shall be based on parameters compatible with the design method being utilized. The seismic loading shall be specified for each of three orthogonal directions (typically plant east–west, north–south, and vertical). The seismic design should be based on either a three-directional excitation, east–west plus north–south plus vertical, combined by square-root sum of the squares (SRSS), or a two-directional design approach based on the envelope of the SRSS of the east–west plus vertical and north–south plus vertical seismic loading.

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