The Von Duprin 48009455 is the OEM dogging cover plate kit for the Von Duprin 78 Wide Stile exit device in fire-rated or less-dogging configurations, documented in the Von Duprin 70 Series Service Manual (doc 116131) as Item 1 in the dogging cover plate and conversion kits diagram. The kit fits both 3-foot and 4-foot device lengths. Finish must be specified at time of order. Per the service manual note, this kit includes parts for a three-piece cover conversion.

This part covers two distinct applications that share the same physical need - closing the dogging slot in the push bar. Fire-rated installations cannot allow dogging, and less-dogging configurations don't include a dogging mechanism. In both cases, the push bar has an open slot where dogging hardware would otherwise sit, and this cover plate seals that opening cleanly. Without the cover plate, the slot is visible and exposed on the push bar face, which creates a tamper opportunity and leaves the device looking incomplete.

Von Duprin Dogging Cover Plate: Fire-Rated Application

The Von Duprin 78-F fire exit hardware device carries a UL listing for fire-rated door assemblies under UL 10C positive pressure conditions. That listing requires the exit device to positively latch the door every time it closes - the latch bolt must project into the strike and hold the door. Dogging defeats that requirement by holding the push bar depressed, which keeps the latch retracted and the door unlatched.

Fire-rated exit devices cannot be held in the dogged position because a fire door that doesn't latch allows smoke and fire to travel through the opening. The National Fire Protection Association and the International Building Code both address this - fire door hardware cannot prevent automatic latching.

When the 78-F is installed on a fire-rated opening, the dogging slot in the push bar body must be covered. Even if no one intentionally attempts to dog the device, the open slot could allow a hex key to be inserted and accidentally engage any residual dogging surfaces. The 48009455 cover plate kit closes the slot definitively.

Von Duprin Plate Kit: Less Dogging (LD) Application

When the 78 device is configured as Less Dogging (LD) - either ordered from the factory without dogging capability or converted in the field from a dogging to no-dogging configuration - the push bar has an open slot where the hex dogging shaft or cylinder dogging hardware would otherwise be. The LD configuration simply removes all dogging hardware, leaving the slot empty.

The 48009455 kit fills that slot with a finished cover plate that matches the device body finish. For facilities where AHJ requirements, security policy, or occupancy classification prohibits dogging on a non-fire-rated exit device, the LD cover plate provides the clean, professional finish that confirms no dogging mechanism is present.

70 Series Parts: 78 Wide Stile vs 75 Narrow Stile Cover Plates

The dogging cover plate family in the Von Duprin 70 Series divides by device width. The 48009455 (this product) is for the 78 Wide Stile device. The companion kit for the 75 Narrow Stile device is the 47999318 - same function, different push bar cross-section. These two kits are not interchangeable. The 78 push bar is physically wider than the 75, so the cover plate geometry differs.

For facilities with both 78 Wide Stile and 75 Narrow Stile devices, two separate part numbers are required - one of each. Confirm the installed device model (78 or 75) before ordering.

For conversion in the other direction - adding cylinder dogging to a non-dogging 78 Wide Stile device - the correct kit is the 48009454 (78 CD Conversion Kit, fits 3' to 4'). The 48009455 covers the slot; the 48009454 fills it with the cylinder dogging hardware package instead.