The 501020-0807 PTFE-Teflon® Flange Insulator is designed for use with NW50 size ISO-KF flanges with 2.0 inches vacuum tubing on one side and a hose or bellow tubing on the other side that is clamped with a model 100318806 ISO-KF toggle flange clamp. Series 49UL flange insulators keep heat from escaping at flange connections for better temperature uniformity in vacuum piping applications. PTFE-Teflon® constructed heater jackets can be used in all critical applications where minimal outgassing, ultra-low particle generation, elevated temperatures up to 200°C, and ease of installation are required. These patented heaters are constructed with fully squared ends and a form fit shape to maximize thermal efficiency and temperature uniformity, minimizing thermal losses and power consumption.