Dampers designed for temperature to 2000ºF+ either internally insulated (refractory lined) or all alloy construction for external insulation. 

http://www.advancedvalve.com/images/special-damper.jpg

• Various seat styles available: tadpole, clearance, scissors, and step (machined or non machined).
• Alloys to suit your needs: inconel, hastalloy, micro alloys, 310 S/S, 330 S/S and other commercially available alloys.
• Refractory lined dampers available with floating metallic liners to eliminate the erosive conditions found in many refractory lined dampers.
• Field proven designs (references upon request).