Butterfly Dampers


Air Systems Butterfly Dampers

Butterfly Dampers, or Butterfly Backdraft Dampers, can be built to customer specifications are ideal for shut off and backdraft prevention applications when system is not in use. Air Systems has created butterfly backdraft shut off dampers for a variety of customers to satisfy their unique criteria. Seal designs include: Swing-Through, Tadpole, and Step-Seat.

Body construction include: Flange duct mounted and roof curb. Option features: custom curb, curb bases and rain cap.


  • Backdraft Prevention


  • Round
  • Square / Rectangular

Blade Operation

  • Gravity Close


  • 110 gauge standard, up to 48″, 7 gauge up to 72″
  • Alumunized, Galvanized, Stainless Steel, Other
  • Duct or roof curbed mounted

Temperature Range (Materials Selected by Applications)

  • Typically up to 400° F standard, above 400° F refer to factory


  • Continuous full length shaft standard, Stub Full Length available
  • Cadmium Plated 1036 Carbon Steel or 304/304L Stainless Steel (SS) – up to 2″ available


  • Sintered Bronze Pressed in Frame (PIF)
  • Stainless Steel Pressed in Frame (PIF)
  • Bolted Flange Block Ball Bearing (Standard on Automatic Dampers)
  • Nitronic High Temp Bushing (Standard for Dampers above 900° F)