Document yrjGYn3xd6jaLvDZ1veYVpMe2

Interoffice Communication Distribution -cm Peggy Marritt October 1, 1981 Subject Relief Valve Discharges {conoco) Attached is a table summarizing all relief valve discharges reported to the EPA under NESHAP since 1975. Future relief valve discharges will be recorded in this table. Peggy Marritt Process Engineer br Distribution JAD, JWW, GLF, MLA, DLD, MJM Process Engineering Environmental File CMC vvc 000019856 TABLE I. RELIEh VALVE DISCHARGES REPORTED TO EPA UNDER NESJIAP REGULATIONS RV/VESSEL 2 relief valves on vinyl barge owned by Choten Barge Co. RV-643/S-207 ASB Vinyl chloride drying beds Relief valve on vinyl ship owned by Unigas Co. of Norway RV-204/C-202 HCL Column RV-209/S-206 Caustic Decanter RV-201/C-201 Quench Column RV-314/S-206 Caustic Decanter DATE 11-03-78 TIME None Given DURATION None Given DISCHARGED(lbs) 900 10-03-79 0945 15 Seconds 1 ,643 5-28-80 1700 7-16-80 1715 None given 30 Seconds 13.6 10,980 10-24-80 0545 10-26-80 0130 8-25-81 1215 3 Minutes 1 Minute 1 Second 2 ,500 5,475 77 DISCHARGED(lbs) 900 1 ,543 13.6 4 2,500 1,990 77 STATED CAUSE Overpressure in vessel's receiving tank. STATED CORRECTIVE ACTION Loading was stopped. Block valve on circulation line from beds was closed when system was placed in service causing beds to overpressure. Opened block valve. Overpressure in the vessel's Loading was stopped. receiving tank. Overpressured due to greater than anticipated inert gas concentration in the col. Opened block valve in vent line to the thermal inciDeration unit. Overpressured due to valve misaliqnment. Emergency shutdown on a cracking furnace. Plugged sparger on 5-207A Opened block valve. None stated. Switched to S-207B. Study the feasibil ity of emergency design changes. VVC 0 0 0 0 1 9 8 5 7 I