1、Lessons Learned Entry: 0104Lesson Info:a71 Lesson Number: 0104a71 Lesson Date: 1992-08-14a71 Submitting Organization: KSCa71 Submitted by: David PenningtonSubject: Pressure System Maintenance Description of Driving Event: Performing work on S70-0613-00-001-0120 to change improperly sized flex hose r
2、estraints. When attempting removal of flex hose, gaseous nitrogen was released due to a partially opened valve in the system. Isolation valve A102736 on the F70-0014 panel was closed to stop the gaseous nitrogen flow to the flex hose. The gaseous nitrogen contained small quantities of N2H4 vapors. T
3、he work authorizing document did not contain instructions or work stops to verify that there was no pressure on the flex hose.Lesson(s) Learned: Work authorizing document failed to include instructions/work stops to verify that there was no pressure on the system; a “close call“ resulted.Recommendat
4、ion(s): System engineers should update work authorizing documents to include verification of zero pressure on systems prior to making repairs.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AProvided by IHSNot for ResaleNo reproduction or networking permitted without
5、license from IHS-,-,-Mission Directorate(s): N/AAdditional Key Phrase(s): a71 Configuration Managementa71 Ground Operationsa71 Hazardous/Toxic Waste/Materialsa71 Safety & Mission AssuranceAdditional Info: Approval Info: a71 Approval Date: 1994-06-02a71 Approval Name: James G. Klinea71 Approval Organization: KSC/HEIa71 Approval Phone Number: 407-867-7614Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
