1、Lessons Learned Entry: 1766Lesson Info:a71 Lesson Number: 1766a71 Lesson Date: 2006-10-24a71 Submitting Organization: GRCa71 Submitted by: Gerald PiaseckiSubject: Use of oil immersion heaters in combustible lquid storage tanks Abstract: National Fire Protection Association (NFPA) Codes and Standards
2、 set the minimum requirements for flammable and combustible liquids storage tanks and related controls. NFPA 30 permits immersion heaters in Class IIIB combustible liquids and other controls are required for more aggressive liquids, or are outright prohibited. This lesson learned provide additional
3、recommendations for immersion heaters used in Class IIIB combustible liquids.Description of Driving Event: A deflagration and fire occurred in 2005 at the NASA Glenn Research Center in Building 124. The building contained a series of storage tanks designed to hold combustible turbine oil (Class IIIB
4、). The tanks were wide and flat so that liquid levels did not fluctuate highly when the oil was pumped out and into the turbine system. On one given day the oil level was low and a deflagration occurred in the storage tank room, emanating from the fill port of the tank. Three operator/mechanics were
5、 in the room at the time. The deflagration threw a fireball out of the fill port which collapsed back into the tank once the atomized fuel was spent. The bedplate of the tank was greatly deflected as a result of the pressure during the deflagration and pre-heating. The immersion heater was exposed f
6、or a time and superheated the surface oil, essentially cracking the oil into light hydrocarbons. The immersion heaters were not required when the unit was to be installed within a building.Lesson(s) Learned: Class IIIB combustible liquids could be cracked into lighter, more dangerous, hydrocarbons w
7、hich require other engineering controls.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Recommendation(s): Do not include immersion heaters when not absolutely necessary. In addition, provide level interlocks to prevent over-heating surface oil.Evide
8、nce of Recurrence Control Effectiveness: NFPA 30 requires these special interlocking controls for lighter hydrocarbons, like those generated through the oil cracking process.Documents Related to Lesson: N/AMission Directorate(s): a71 Space Operationsa71 Sciencea71 Exploration Systemsa71 Aeronautics
9、ResearchAdditional Key Phrase(s): a71 Safety and Mission Assurance.a71 Safety and Mission Assurance.Advanced planning of safety systemsa71 Safety and Mission Assurance.Configuration Change Controla71 Safety and Mission Assurance.Early requirements and standards definitionAdditional Info: a71 Project: Safety Mission AssuranceApproval Info: a71 Approval Date: 2007-07-13a71 Approval Name: ghendersona71 Approval Organization: HQProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
