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<br />,. <br /> <br />....,.,05/11/99 10: 22 <br /> <br />'5'281'0 1035 <br /> <br />HAAG-HOUSTON ~~~~ SCOTTSDALE INSUR <br /> <br />@007 <br /> <br />, <br /> <br />Littleton Claims <br />(Alliance Recovery Services) <br /> <br />Page 6 May 6,1999 <br />Haag File: 2990056-247/238 <br /> <br />two small portions of the involved vessel but does not have plans for any additional work <br />or metallurgical analysis. <br /> <br />Following discussions with Mr. Don Hutchins, we arranged for remains of the involved <br />vessel to be transported for storage at Hicks Fire Determination .,storage facility near <br />Conroe, Texas. Work to be done includes selection of pieces to be cut from the vessel and <br />submitted for metallurgical examination and analysis. <br /> <br />DISCUSSION <br /> <br />standards for pressure vessels are provided for by the American Society of Mechanical <br />Engineers (ASME). Vessel configuration and required safety devices are included in <br />ASME Section VIII, Div. 1, which al60 provides specific information concerning pressure <br />relief valves_ <br /> <br />The PRY on the involved vessel appears to have been rated 350 psi, and the storage <br />vessel was tested at 300 psi. A PRY rated 250 psi would be a better choice for the <br />application.. However, all evidence indicates the vessel ruptured at a pressure below 200 <br />psig; thus, the PRV was not a factor for the cause of failure. The lack of full penetration <br />in the weldment between the end cap and the vessel body substantially decreased the <br />maximum possible strength at that location. We cannot exclude the relatively poor <br />weldment as a major cause for rupture of the vessel. Corrosion may have contributed by <br />further weakening the weldment. Metallurgical inspection results will shed additional light <br />on the reasons for failure. <br /> <br />PRELIMINARY CONCLUSIONS <br /> <br />Based upon our Inspection and the information discussed above, we have reached the <br />following preliminary conclusions: <br /> <br />- <br />1 . The involved refrigerant storage vessel did not have a nameplate as required <br />by ASME standards. . <br /> <br />2. Testing of the involved storage vessel was at 300 psi and the PRV was rated <br />350 psi. <br /> <br />3. Failure of the vessel occurred at a pressure below 200 psi. <br /> <br />, ' <br /> <br />05/11/99 TUB 08: 18 [TX/RX NO 9655] ~ 007 <br />