#101 Stopping in-line leakage, with the bonus of better fugitive emissions control.  Problem: Personnel at a large Texas processing facility identified a valving problem in their plastic formulation unit. With the ball valves in the application, there was an unacceptable level of line leakage past the valve seats. This leakage was due to particles and fibers that were binding between the seat and ball, damaging the sealing surface. Plant engineers evaluated a number of alternative valves. The objectives of this evaluation included: Improved in-line sealing. Improved overall operating reliability. Better control of fugitive emissions. Greater long-term economy.  Solution: They decided on the Tufline sleeved plug valve with the tertiary top seal option. There were five primary features that convinced them. The valve offered impressive in-line sealing characteristics. Adjustable, positive, 360-degree in-line sealing is provided by the large, full circumferential, chemically inert PTFE sleeve. The sealing area was much larger and more reliable than that offered by the ball valve. A second factor was the Tufline sleeved plug valve's tertiary top seal option. This stem sealing system economically meets stringent fugitive emissions regulations without add-on packing or springs. The secondary seal is a true, fully-redundant back-up sealing systems. The primary seal is accomplished by the interaction of the plug, sleeve, and body, so flow media does not reach the stem. The top seal includes a fire-tested component. The valve's price (even with the top seal option) is close to that of a standard valve. They also considered the valve's light weight, compact, cavity-free design, and simple actuation. Plant personnel also visited the Tufline manufacturing plant. They were impressed with the Tufline quality assurance program.  Results: Tufline sleeved plug valves with the tertiary top seal option have now been in service at the facility for several years, providing improved in-line sealing and superior fugitive emissions control with less maintenance. Index of all performance report case histories.