#103 Valve longevity in a high pressure ash water system.  Problem: A Colorado firm wanted to maximize valve service life in its high pressure ash water system.  Solution: The local Tufline Sales Engineer recommended the Tufline sleeved plug valve. One of the keys to this valve's exceptional service life is the PTFE sleeve. The PTFE sleeve is between the plug and the body. The plug acts as a wedge, pressing the sleeve against the body, assuring a uniformly tight seal. For superior in-line sealing, the PTFE sleeve completely surrounds the plug. In most applications, this full circumferential port-to-port sealing surface assures tight shutoff even after years of service. Compare the sealing surface area of sleeved plug, gate, and ball valves. The sleeved plug valve provides the largest sealing surface by a wide margin. Also unlike gate and ball valves, there are no cavities. Cavities where flow media can accumulate tend to shorten the service life of ball and gate valves. 360 port defining lips protect the PTFE sleeve from the erosive action of the entrained ash. Index of all performance report case histories.