Galvanized Steel Double Leaf Automatic Fire Vents

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Williams Brothers - WB BILCO TYPE DSH Series Galvanized Steel Double Leaf Automatic Fire Vent

The Best Double Leaf Automatic Smoke Vent in the Industry!

WB Type DSH 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 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 Reinforced
  • 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: UL-listed and FM Approved, Complies with UL 790 Class A (burning brand test)


  • Single Door: See Model Type SV
  • Custom Sizes: Available on Request

Models Available

  • DSH4848 Steel – 48″ x 48″
  • DSH4872 Steel – 48″ x 72″
  • DSH4890 Steel – 48″ x 90″
  • DSH4896 St Curb-Al Cvr – 48″ x 96″

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