The Xomox® XLD lined butterfly valves have thick PFA or PTFE liners that provide resistance to permeation, extending product life and improving safety. The valves feature low torque operation enabled by an innovative sealing mechanism and bearings, allowing the use of smaller and more economical actuators. The substantial liners, live-loaded stem sealing system, improved disc design, and other features provide integrity, safety and cost advantages for the valves.