ASME B31.8S:2001 pdf free download

ASME B31.8S:2001 pdf free download.MANAGING SYSTEM INTEGRITY OF GAS PIPELINES.
In a performance-based program, the operator mayconsider alternate models that calculate impact areasand consider adiditionai factors such as depth of buriaithat may reduce inpacL areas. The operalor shall countthe number of houses and individuai units in buildingswithin the potential impact area. The potential impactarca cxtends from the centcr of the first affccted circlcto the center of the last affected circle (see Fig. 3 foran illustration).This housing unit count can then beused to help determine the relative consequences of arupture of the pipeline segment.
lhe ranking of these areas is an important elementof risk assessment. Determining the likelihood of failurcis the other important element of risk assessment (seesections 4 and 5).
3.3Consequence Factors to Consider
Whcn cvaluating the consequences of a failure withinthe impact zone, the operator shall consider at lcastthe following:
(a)Population density
(b) Proximity of the population to the pipeline (including consideration of manmade or natural barriersthat may provide some level of protection)
(c) Proximity of populations with limited or impairedmobility (e.g.. hospitais.schools，child-care centers,retirement communities. prisons, recreation areas) partic-uiariy in unprotected outside areas
(d)Property damage
(e) Environmentai damage
Effects of unignited gas releases
(g)Security of gas supply (e.g.. impacts resultingfron interruption of service)
(h)Public convenience and necessity
(i)Potential for secondary failures
important defects and material properties are in model-ing the characteristics of the failure.
4 GATHERING，REVIEWING，AND INTEGRATING DATA
4.1 General
This section provides a systematic process for pipeline operators to collect and effectively utilize the data elements necessary for risk assessment. Comprehensive pipeline and facility knowledge is an essential compo-nent of a performance-based integrity management pro-gram. In addition, informaion on operational history, theenvironment around the pipeline，mitigation techniquesemployed, and proccss/proccdure revicws are also neces-sary. Data are a key clement in the decision makingprocess required for program implementation. Whenthe operator lacks sufficient data or where data qualityis below requirements，the operator shall follow theprescriptive based processes as shown in Nonmandatory Appendix A.
Pipeline operator procedures，operation and mainte-nance plans,incident information,and other pipelineopcrator documents specify and require collection ofdata that are suitable for integrity/risk assessment. Inte-gration of the data elements is essential in order toobtain complete and accurate information needed foran integrity management program.