The control of low pressure high temperature gases can be economically achieved using the Leeds Valve swing clear and step seat design. The low breakout and re-seat torque allows the valve to be automated with small simple actuators and can be used with lever operators for trimming control. Manufactured in cast high temperature materials the construction can utilise alloys which would not readily be fabricated. Shafts, bearings and gland packing are carefully selected to eliminate sticking and ensure the valves operate smoothly at the elevated temperatures. One of the most popular materials used by Leeds Valve is “Heat Resistant Cast Iron”, cast iron with the addition of a small percentage of nickel and chromium, allowing use up to 650C. Where there may be corrosion problems, high grade stainless steels and specialist alloys like 37/18 Ni Cr can take the temperature up to 800C. Depending on temperature, the swing clear and step seat valve can maintain ANSI / FCI 70-2 class I to class III leakage adequate for low pressure gas control. If the gases contain abrasive particles then disc, shaft and body can be hard faced.