1、Lessons Learned Entry: 0617Lesson Info:a71 Lesson Number: 0617a71 Lesson Date: 1998-12-18a71 Submitting Organization: MSFCa71 Submitted by: Lorraine RabySubject: Test Stand 116 Liquid Oxygen Fire Mishap Investigation Description of Driving Event: At approximately 4 p.m. on June 7, 1996, a liquid oxy
2、gen fire occurred in the “A“ Leg of the LOX feed system for the 750k lb. position of Test Stand 116 located in the East Test Area of MSFC. The fire occurred as the “A“ Leg engine shutoff valve reached the “20T open“ position while closing after completion of the fourth of a series of six planned set
3、 point tests. These test were being conducted to provide data for establishing the correct throttle valve setting for subsequent planned hot fire testing of a 650k lb. Thrust Chamber Assembly provided by Rocketdyne. At the time of ignition, the “A“ Leg shutoff valve had closed far enough to permit i
4、t to take control of the LOX flow from the venturi. The LOX fire started in the seat region of the valve, progressed from the engine shutoff valve outlet to the test article within 120 ms, and burned for approximately 25 seconds. For the first 8 seconds, the fire was fed by high pressure LOX. The fi
5、re partially consumed the lower part of the engine shutoff valve body, the two elbows and straight pipe section that connected the engine shutoff valve and the test article. The test article, all instrumentation devices, hydraulic fluid lines, control wires and cables on the stand were destroyed. Th
6、e hydraulic fluid fire primarily charred pipe insulation and coated the test stand and its equipment with soot.Lesson(s) Learned: The purpose of lessons learned is to provide a global overview of what value-added engineering design and testing practices can be obtained from studying this mishap. In
7、addition, improvements in other processes are also pointed out. The lessons learned are not intended to be additional “recommendations,“ however, their application is certainly intended to be implemented as good engineering practice. The board, in most cases, related the lessons learned to their fin
8、dings and recommendations where applicable, however, they did not feel constrained by them. The lessons learned are as follows:Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1. All components proposed for use in high pressure systems should have dem
9、onstrated functionally in an application and environments comparable to their intended use. If the above is not feasible, the component design drawing should be fully assessed or the system should be tested under appropriate conditions in an inert environment and disassembled and inspected prior to
10、use in oxygen environments.2. Chairpersons of Design Reviews, ORIs, etc., should make sure that review documentation accurately reflects the hardware under review.3. Prospective suppliers should be required to provide historical data to verify their qualification to supply components for the specifi
11、ed environment and intended use.4. Performance Specifications for purchases of high pressure components must include requirements for demonstrated capability in the media and environment in which the component is to be used.5. Extreme caution should be exercised when a significant discrepancy exists
12、 between expected and actual test data. Testing should not proceed until the discrepancy has been explained to the satisfaction of appropriate discipline experts, and the test team deems it acceptable to proceed.Recommendation(s): See Lesson(s) Learned.Evidence of Recurrence Control Effectiveness: N
13、/ADocuments Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Configuration Managementa71 Environmenta71 Parts Materials & Processesa71 Test & VerificationAdditional Info: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Approval Info: a71 Approval Date: 1999-03-29a71 Approval Name: Frank Hepburna71 Approval Organization: CR10a71 Approval Phone Number: 205-544-1806Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
