Storeroom Lock Retrofit with Fire-Rated Door
A hospital maintenance supervisor asks you to replace a failing mechanical storeroom lock on a 90-minute fire-rated corridor door. The existing lock is a Grade 2 cylindrical lever set with a 2-3/4" backset. The door is 1-3/4" thick, hollow metal, and the frame is welded. The supervisor wants to keep the same keyway and avoid rekeying the department. You have a replacement Grade 1 cylindrical lock with a 2-3/4" backset and a standard 161 cutout. The existing door has a 2-1/8" cross-bore and a 1" edge bore. The supervisor mentions that the door sometimes drags on the threshold and that the closer is adjusted too strong. The facility uses a master key system with a strict key control policy. The lock must remain fire-rated and meet ADA lever requirements. You have a 2-hour window before the corridor must be back in service.
1. What are the key code and fire-rating considerations before you begin the swap?
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First, verify that the replacement lock is listed for use on a 90-minute fire door. The lock must bear a UL listing (e.g., UL 10C or NFPA 252) for fire-rated openings. The existing door has a 2-1/8" cross-bore and 1" edge bore, which matches the standard 161 cutout, so no door modification is needed. However, you must check that the lock's latch bolt is rated for fire doors (usually a stainless steel latch with a fire-rated label). The keyway must match the existing master key system, but you cannot simply swap cylinders if the new lock uses a different cylinder format. You need to either transfer the existing cylinder (if compatible) or rekey a new cylinder to the existing master key system. Since key control is strict, you must follow the facility's key control procedures, including documenting the new key and ensuring the old cylinder is returned. ADA compliance requires a lever handle that is easy to operate without tight grasping, and the lock must be operable with one hand. Finally, the door closer adjustment and dragging threshold may affect the lock's ability to latch properly; you should address these issues to ensure the door closes and latches securely, which is also a fire door requirement.
2. How would you handle the keying to maintain the master key system and key control?
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You should first identify the keyway and the master key system's structure (e.g., master key, sub-master, change key). If the new lock accepts the same cylinder type as the old, you can transfer the existing cylinder, preserving the keying and avoiding rekeying. If not, you must obtain a new cylinder with the correct keyway and pin it to the existing change key. Because key control is strict, you must not duplicate keys without authorization. You should request the new key from the facility's key control office, which will cut a key from the existing bitting and log it. The old cylinder should be returned to key control for disposal or reconditioning. You must also update the key control records to reflect the new lock and key. If the lock is part of a master key system, ensure the new cylinder does not compromise the system's integrity (e.g., do not use a different keyway that would require a separate key). Document all actions and obtain the supervisor's signature.