Document O3mrmM5ekKo0DryeE0Rmp2eDM

htitCHEMICALS INTEROFFICE / LAKE CHARLES TO FROM Glenn Work Lamar White DATE SUBJECT April 18, 1975 Sampling for VC Above Rupture Disc As per your request on April 10, I sampled the vapor space between the rupture disc and SRV on several vessels in the Vinyl Plant. Only, vessels on which the pressure gauge on the R/D showed 0# were tested. In some cases, even when the gauge showed no pressure, a slight seepage could be detected when the bleed valve was opened. These R/D's all showed a presence of organics. Two vessels were found on which tfiej gauge showed 0# and where no seepage or vapors could be detected visually, by touch, or sound. These vapor spaces also showed organics present (see table). j '% On April 16, the two R/D's that tested positive, even though there was no apparent pressure above them, were retested using the Century Meter and the lab's new HNU instrument. The HNU, unlike the Century Meter, is selective for Vinyl. Both R/D's again checked positive for VC (see table). The numbers indicated by the instruments cannot be used as an absolute value since we were unable to keep the instruments from drawing in outside air. In addition, the Century Meter cannot distinguish between various organics such as Vinyl and EDC. LW/cg cc: R. P. Lynch