Document 50JxmgV89G2a0NGGb3q0Zg9bJ

XT Occidental Chemical Corporation PVC Resins/PVC Fabricated Products MEMO ToDISTRIBUTION ____________________________ From J. A. KING Subject THIRD REPORT OF 1984 VCSA MEETING Date MARCH 7, 1985 Attached is the last report of the conference. Concerning Item A, 7, Setting of Relief Valves: Vista had a premature failure of a rupture disk, and the 6" x 8" relief valve did not reseat properly. Before the event, the blow down ring of the valve had been "chattering." Vendor advised adjusting the setting to 32 notches where the normal was 16, midway between open and closed. In error, set it at 9 notches where the valve could not reseat. Setting of these valves is difficult to do in place. Vista, however, did so at'32 notches and with three tests with both air and water pressure found the valve to reseat properly. At lower settings, chattering again occurred. Chattering can damage the seat. Once adjusted, the setting does not change - drift. sK A. KING JAK:pl1 Attachment Distribution: With AttachmentsR. W. Arnold J. Boyette, Addis C. W. Engblom G. D. Lloyd C. MacCary, Brl. R. White, Brl. L. Wood, Box 728, Niagara Falls Without Attachments- D. L. Lull R. D. Luss K. H. Garner R. J. Loughin K. P. Hochschwender D. J. Baldwin T. E. Moses I. C. Power M. W. Handler, Addis R. Diehl, Addis T. Nasife, Brl. J. Mitzner, Brl. R. Shaffer, Brl. OCC 3179