ASME HPS pdf free download
ASME HPS-2003 pdf free download.PREPARATION OF TECHNICAL INQUIRIES TO THE HIGH PRESSURE SYSTEM COMMITTEE.
The objective of Section 2000 is to describe“hazards” which may be present in high pressure systems. The word“hazard” implies the potential to do damage. Particular emphasis is placed on hazards which are significantly enhanced by the presence of high pressure. Some of the more probable hazards are discussed in this Section, but one should recognize that all hazards can not always be anticipated from past experience. A specific listing and quantification of hazards shall be developed very early in the planning, siting, and design of any new high pressure facility. The intent of such a review is to enable the owners and operators of high pressure systems to take positive action for a safe system. [2] [4] [11] 2101 Leak Before Break Mode Generally, containment of high pressure demands high stress in structural materials. This requires a Designer to select higher strength materials, to use smaller design factors, or to use heavy wall construction. Hazards resulting from the failure of high strength materials under high stress often give lttle warning prior to their occurrence. For example, subcritical crack growth in high strength alloys under cyclic, high stress amplitudes, and/or in the presence of corrosive or embrittling environments, is extremely hazardous. Growth of such cracks to critical dimensions can lead to sudden and catastrophic release of the contained energy in the system. A “leak-before-break” mode of failure is preferred in the design, and the use of materials having low fracture toughness should be avoided. [2] [4] [10] [16] [20] Engineering or designing“preferential failure modes” into high pressure systems is extremely important. Among these concepts are: the inherent leak-before- break material response mode, placement of pressure relief devices or structures at crucial locations in the system, and the design of joints such as flanges and/ or bolts to yield. Careful attention shall be given to volume rate of release and safe paths for exhausting such releases.
2200 HAZARDS RELATED TO RELEASE OF CONTAINED ENERGY
The sudden brittle-like fracture of a highly pressurized vessel, pipe, or component may result in the acceleration of fragments, vessel components and contents, and adjacent structures to high velocity. Contained energy is often expressed as an equivalent weight of TNT explosive in order to describe this hazard. [5] [6] [8]
2201 Type of Energy Release
The released energy may consist of pressurized fluid energy of expansion, the strain energy stored in the structural containment system, and any chemical or thermal energy which might simultaneously participate in the release. The magnitude of contained energy is strongly dependent on the pressure, volume, and temperature of contained material. The rate of vessel rupture increases with high stress that may be present in high pressure systems. Under certain fast release rates, blast-like shock waves may result and the shock front pressure may be sufficient to injure personnel and damage property and/or control systems. Release of a large amount of contained energy in a closed room may result in a significant overall pressure rise. Small diameter jet releases of fluids from high pressure systems may penetrate the skin and other vulnerable parts of the body. If the contained material is hot or corrosive, someone may get burned. An evaluation O the energy contained in a high pressure system shall be conducted early in the design phase of the system.ASME HPS pdf download.
