The 502010-0803 Polyimide Flange Insulator is designed for use with NW25 size ISO-KF flanges with 1.0 inches vacuum tubing on both sides and clamped with a model 100318803 ISO-KF toggle flange clamp. Series 49UL flange insulators keep heat from escaping at flange connections for better temperature uniformity in vacuum piping applications. Polyimide 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.