1、Lessons Learned Entry: 0534Lesson Info:a71 Lesson Number: 0534a71 Lesson Date: 1997-04-11a71 Submitting Organization: JSCa71 Submitted by: Philip R. LewisSubject: Materials Compatibility: Verifying Design Acceptability Prior to Manufacture and Distribution of Hardware Description of Driving Event: S
2、pace Station Oxygen quick disconnects (QDs) used silicon grease in the flow path of moderate to high pressure oxygen. The auto ignition temperature for this grease is 500 degree Fahrenheit and with pressures of 200 psia and above, adiabatic compression could have caused this grease to ignite, result
3、ing in a catastrophic event on board. The material rating of the silicon grease stated in the Material Identification Usage Agreement (MIUL) was for 30% or less Oxygen concentrations at 14.7 psia or lower pressures, and not that of 100% O2 at elevated pressures. The vendor failed to observe that the
4、 test environment used to determine the MIUL rating as listed in the Materials and Processing Technical Information System (MAPTIS) did not match the actual operational environment. The error was caught by NASA materials and process engineers and representatives of Safety, Reliability, and Quality A
5、ssurance, but not before some of these QDs had already been shipped for installation in Node 1.Lesson(s) Learned: Material incompatibility issues, as well as material compatibility reviews, should be conducted and approved prior to the shipment of any flight hardware.Recommendation(s): Review of the
6、 MIULs must be accomplished by knowledgeable personnel (such as Materials & Processes experts) familiar with the hazards of the working environment.Evidence of Recurrence Control Effectiveness: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N/ADocum
7、ents Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Parts Materials & ProcessesAdditional Info: Approval Info: a71 Approval Date: 1997-04-16a71 Approval Name: Ronald A. Montaguea71 Approval Organization: NA3a71 Approval Phone Number: 281-483-8576Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
