1、Lessons Learned Entry: 0636Lesson Info:a71 Lesson Number: 0636a71 Lesson Date: 1999-07-14a71 Submitting Organization: MSFCa71 Submitted by: John NebrigSubject: Incorrectly Installed Fitting Description of Driving Event: On 7/12/99, a mechanic was performing a verification leak test (using a 2900 psi
2、g gaseous nitrogen pressure source) of a 1/2“ hand valve when an incorrect fitting blew out. The mechanic erroneously installed a 1/2“ AN male fitting into the 1/2“ NPT female port of the valve body. The fitting was attached to a high pressure flex hose when the failure occurred. This flex hose had
3、Kellum restraints that prevented damage to equipment and injury to personnel.Lesson(s) Learned: Identification and installation of fittings requires detailed attention. During the investigation, it was found that the appearance of the 1/2“ NPT female port was tapered. The NPT female port had a taper
4、ed/finished area on the port face very similar to an AN port face. Careful inspection of the fitting and port is required.Recommendation(s): 1. Retrain all technicians in the identification and installation of pressure fittings.2. Review the close call at the next safety meeting.Evidence of Recurren
5、ce Control Effectiveness: N/ADocuments Related to Lesson: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N/AMission Directorate(s): a71 Exploration Systemsa71 Aeronautics ResearchAdditional Key Phrase(s): a71 Energetic Materials - Explosive/Propella
6、nt/Pyrotechnica71 Ground Equipmenta71 Pressure Vesselsa71 Test Facilitya71 Test & VerificationAdditional Info: Approval Info: a71 Approval Date: 1999-09-29a71 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-,-,-
