Last week I published a post about strike hooks, and I didn’t have a good photo of one installed. David Barbaree of Atrium Health came through for me, so I’m republishing this post with David’s photos.
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Last week I shared a “What’s that?” post about an LCN CUSH shoe support, and my friend Lloyd Seliber requested a post about the Von Duprin strike hook. Yes – I do take requests! 🙂
This is a great topic for a post, because it’s a common problem I see in the field – the incorrect strike installed, or the strike hook missing. The strike hook is part of the assembly for the 499F strike. One of the common applications for this strike assembly is with the Von Duprin 9927-F surface vertical rod fire exit hardware when it is installed less bottom rod (LBR). This strike is also used with some removable mullion applications.
The strike hook is installed on the face of the door, and inserts into the strike when the door closes. The purpose is to help keep the door and hardware properly aligned and latched during a fire test (and during a fire). If the 499F strike assembly is required by our listings for a particular application, and the correct strike and strike hook are not installed, the fire door assembly may not perform as designed and tested during a fire.
The photos below, sent by David Barbaree of Atrium Health, show two installations – one where the required strike hook is installed and another where the hook is missing.
One of the common field issues I see is existing surface vertical rod fire exit hardware that has been modified to remove the bottom rods and latches for a less bottom rod (LBR) application. This change will typically require the addition of an auxiliary fire pin, AND changing the strikes from the original 299F strikes to 499F strikes. The installation instructions for the auxiliary fire pin show this change to the strikes.
The strike on the left below is the standard 299F strike that would be installed with 9927-F fire exit hardware with top and bottom rods and latches, and the strike on the right is the 499F strike with the strike hook that would be installed with the less bottom rod (LBR) application.
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Good to know!! Thank you.
Lori,
Don’t they require a spring for the baseplate change out when changing to LBR as well?
That’s a great question, Rian! The devices that we currently manufacture don’t require the spring to be changed, but yes – older devices would require a new spring. I don’t know the date when we started using the same spring for both types (LBR and non-LBR), but if the hardware is more than 20ish years old and is being changed to LBR in the field, the springs should be checked/changed along with the strikes and the auxiliary fire pin. I would also recommend checking with the door and hardware manufacturers to make sure the change is permitted by the listings for that older installation.
Thanks for asking!
– Lori