In the light of the low reliability and high failure rate of beam pumping units, a system reliability synthetic appraisal and distribution method considering predicted failure rate is introduced.

针对游梁式抽油机整机可靠性差、故障率高，必须进行系统可靠性设计的现状，提出一种考虑预计失效率的系统可靠性综合评分分配法。

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"The failure rate was higher than predicted as part of the certification process and the possibility that a short circuit in a single cell could propagate to adjacent cells and result in smoke and fire must be reconsidered, " said Deborah Hersman, the head of NTSB.

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