The non-combustible PVF slurry then passes to one of three insulated slurry holding tanks
(numbered 1, 2, or 3) in the tank farm adjacent to the production building (Figure 1).
Under normal operating conditions, slurry is pumped to slurry tank 3. Slurry tank 3 is
newer than slurry tanks 2 and 1; it had been replaced in 2009 due to corrosion2. Slurry
tanks 2 and 1 were used as overflow storage space in the event slurry tank 3 was filled and
slurry tank 1 was generally kept empty of slurry.
If the slurry flash tank level is too high, hot slurry passes through the flash tank overflow
line directly into slurry tank 2. A liquid trap (seal loop) on the end of the overflow line
inside slurry tank 2 was designed to prevent VF vapor and steam from passing directly from
the flash tank into the slurry tank. The PVF slurry is then pumped from the slurry tanks to
the Tedlar production area for further processing. PVF is used in a variety of applications as
a film or a surface protector due to its resistance to weathering and flammability-lowering
properties.
2.1 PHYSICAL, CHEMICAL, AND BIOLOGICAL PROPERTIES OF VINYL FLUORIDE
VF is a colorless, highly flammable gas at ambient conditions with an ether-like odor3. VF
vapors are heavier than air and will accumulate in low areas. VF is classified as a reasonably
anticipated human carcinogen4. National Institute for Occupational Safety and Health
recommends an exposure limit of 1 ppm as a time weighted average and a ceiling limit of 5
ppm for workers.