Document bBgD5gVo1nddLpd3bRkrMXOb1

CHEMICALS XMiBlT O' VINYL CHLORIDE SAFETY ASSOCIATION MEETING - 1984 SUBJECT: CORROSION IN RECOVERY SYSTEM SPEAKER: N. (Nino) Pellarin PVC Technical Supervisor Esso Chemical Canada OCC 3174 CHEMICALS EXHIBIT T VINYL CHLORIDE SAFETY ASSOCIATION MEETING - 1984 CORROSION IN RECOVERY SYSTEM BACKGROUND: - TWO 316 SS INERTS DRUMS IN RECOVERED VCM OPERATION. UPSTREAM PIPING PRIMARILY CS. - DRUMS ARE EXPERIENCING PIT CORROSION. - PITTING IS REPAIRED BY LIGHT GRINDING AND WELDING. - CONCERNS: (1) INTEGRITY OF DRUMS: LEADS TO ENVIRONMENTAL RELEASE. (2) REPAIR TECHNIQUE: LEADS TO CSCC OCC 3175 CHEMICALS Exhibit J CORROSION IN RECOVERY SVSTEM VINYL CHLORIDE SAFETY ASSOCIATION MEETING - 1984 FIG. 1; BREAKDOWN OF OXIDE FILM FIG. 2: FORMATION OF PIT OCC 3176 CHEMICALS EocmeiT j~ VINYL CHLORIDE SAFETY ASSOCIATION MEETING - 1984 CORROSION IN RECOVERY SYSTEM MECHANISM: - CORROSION PROTECTION FOR SS DRUMS PROVIDED BY OXIDE LAYER. - IRON CHLORIDES CHEMICALLY "BREAKDOWN" THE OXIDE FILM. - STAGNATION PREVENTS RE-PASSIVATION. - HYDROCHLORIC ACID ATTACKS THE UNPROTECTED SITE. - A PIT DEVELOPS. - PROPAGATION ASSISTED BY THE ELECTROCHEMICAL EFFECT. - FACTORS THAT ACCELERATE PROCESS: (1) ACIDITY (2) TEMPERATURE OCC 3177 CHEMIC^ Exhibit- J" VINYL CHLORIDE SAFETY ASSOCIATION MEETING - 1984 CORROSION IN RECOVERY SYSTEM CORRECTIVE ACTIONS: - SHORT-TERM: PURCHASED GL VESSEL TO REPLACE MAIN SS DRUM. ONE DRUM OPERATION TO PREVENT STAGNATION. - LONG-TERM: CONSIDERING WAYS OF CONTROLLING OR ELIMINATING FACTORS. OCC 3178