1、Lessons Learned Entry: 0240Lesson Info:a71 Lesson Number: 0240a71 Lesson Date: 1993-07-17a71 Submitting Organization: LERCa71 Submitted by: S. PapellSubject: Pneumatic Explosion Description of Driving Event: A cover plate bolted to the top of a high pressure helium filter was blown off and the conte
2、nts of the filter (pyrex wool and silica gel) were expelled. The resulting failure occurred because there were only three bolts holding the cover in place instead of the sixteen bolts required to fill all the bolt holes. The filter was pressurized to 1700 pounds per square inch with helium when the
3、pneumatic explosion occurred.Preceeding the accident, as part of a maintenance program, the filter cover was removed for cleaning and reactivation. The bolts were frozen and difficult to remove. After three bolts were removed, the balance of them were cut off. When the cover was reinstalled, the thr
4、ee good bolts were put on but other bolts were not available to complete the bolt hole circle. Without knowledge of the incomplete assembly, the system was pressurized by the test crew resulting in the pneumatic explosion.Lesson(s) Learned: Maintenance programs that include disassembly and reassembl
5、y of test cell components require a check out procedure to establish work completion before initiating a test run.Recommendation(s): Training should emphasize the importance for team members to check the actions of other members to prevent initiation of hazardous situations.Evidence of Recurrence Co
6、ntrol Effectiveness: N/AProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Documents Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Logisticsa71 Pressure VesselsAdditional Info: Approval Info: a71 Approval Date: 1994-06-08a71 Approval Name: Maria Havenhilla71 Approval Organization: LERC/EBASa71 Approval Phone Number: 216-977-1483Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
