Since I might be getting a used Simplex 4251-20 pull, and I wana know if my b-key from my 4099-9006 pull would work? Since it the 4251-20 has the lock with the letter “B” on it.
I’m not a Simplex technician or even with the company at all, but I’m fairly certain the majority of Simplex devices that take keys use the B key (with the exception of some like duct detector key switches).
To answer OP’s question: Yes. The more things change, the more they stay the same.
Yes B (cat 30) key is global for those devices with the exception of the handful of devices requiring an AH key, hex, or A key for some old STR equipment.
Some more details:
Some annunciators are operated with an A key, and on some (the “Remote Command Center” kind that’s mounted in large cabinets) you actually need both keys - a B key to open the cabinet and an A key to enable the controls! (very poor design, in my opinion…)
Canadian 2-stage pull stations also use an A key for the 2nd stage.