Document aJn9wZLRVde9gwNyM7bZD8mky

t cc JWW-RB-MLA-PLF-DLD-MWC-MGH-ESW-JCL ke Charles VCM Plant CERTIFIED MAIL #8090985 RETURN RECEIPT REQUESTED conoco) Conoco Chemicals Company A Division of Conoco Inc. P.O. Box 605 Westlake. LA 70669 (3181 491-5211 'IlLUJts May 16, 1983 Gus VonBodungen Air Compliance Division Department of Natural Resources P 0 Box 44066 Baton Rouge, LA 70160 Dear Mr. VonBodungen: The following is a report of a relief valve discharge of vinyl chloride at the Conoco Chemicals VCM Plant in Westlake, Louisiana which occurred on May 6, 1983. Reporting of a relief valve discharge is required under Section 61.65(a) of the National Emission Standard for Hazardous Air Pollutants for vinyl chloride. The relief valve on the tube side of the VCM Column Feed/Bottoms Inter changer discharged an estimated 1226 lbs. of VCM at 7:00 pm on May 6, 1983. The VCM was discharged due to an overpressure of the system and was vented to the atmosphere via the vent scrubber stack. The estimate of the quantity of VCM released was based on a maximum re lease time of 1.5 minutes for the 3" x 4" Consolidated Type 1905-Kc re lief valve. The set pressure of the relief valve is 200 psi. The calculational method used was from Consolidated's Safety Relief Valve Catalog No. 1900B. The overpressure condition was caused by deviation from established operating procedures. During the startup of the VCM Column following a maintenance shutdown, the feed pumps from the VCM Check Tanks through the interchanger to the column, were started. The manual block valve on the VCM Column feed line downstream of the inter-' "" changer was closed, which caused an overpressure condition and the subsequent lifting of the relief valve at the interchanger. Corrective action to prevent a recurrence includes counseling of the operators on following established procedures. Please let me know if you have any questions concerning this report or if you require any additional information. Sincerely, Plant Manager - Conoco VCM rr nirl' Whittinoton