Galvanized Steel Automatic Fire Vents

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Williams Brothers - WB Type SV Series Galvanized Steel Automatic Fire Vent

The Best Automatic Smoke Vent in the Industry!

Type SV Series automatic fire and smoke vents are available in a number of standard UL listed and FM-approved sizes. Features include fully insulated covers and galvanized steel or aluminum construction. By Bilco.


  • Cover: 14 Gauge G-90 Paint Bond Galvanized Steel – Breakformed, Hollow-metal Design with 1″ Concealed Fiberglass Insulation, 3″ Beaded, Overlapping Flange, Fully Welded at Corners, and Internally
  • Frame: 14 Gauge G-90 Paint Bond Galvanized Steel
  • Curb: 12″ in height with integral capflashing, 1″ fiberboard insulation, fully welded at corners, and 3-1/2″ mounting flange with 7/16″ holes provided for securing frame to the roof deck
  • Finish: Alkyd Base Red Oxide Primer
  • Latch: Positive Hold/Release Mechanism Controlled by Single Fusible Link – Designed to Hold Cover Closed Against a 90 psf (438 kg/m2) Uplift Force
  • Fusible Link: 165°F UL Listed Fusible Link
  • Hinges: Heavy-duty, Type 316 Stainless Steel Pintle Hinges with 3/8″ Hinge Pins
  • Lift Assistance: Engineered Composite Compression Spring Tubes, Steel Compression Springs with Electrocoated Acrylic Finish
  • Gasket: Extruded EPDM Rubber Gasket (permanently adhered to cover)
  • Hardware:  Hardware is Zinc Plated/Chromate Sealed
  • Loading: Reinforced for 40 psf (195 kg/m2) Live Load
  • Approvals: Complies with UL 790 Class A (burning brand test)


  • Double Leaf/Door: See Model Type DSH
  • Custom Sizes: Available on Request

Models Available

  • S-20SV Steel – 36″ x 30″
  • NB-20SV Steel – 30″ x 54″
  • L-20SV Steel – 30″ x 96″
  • S-40SV St Curb-Al Cvr – 36″ x 30″
  • L-40SV St Curb-Al Cvr – 30″ x 96″
  • S-50SV Aluminum – 36″ x 30″
  • NB-50SV Aluminum – 30″ x 54″
  • L-50SV Aluminum – 30″ x 96″

Manufactured by Bilco for The Williams Brothers Corporation of America. MADE IN USA.