The other day, someone asked me how a fire door with fire exit hardware can pass the hose-stream portion of the fire test. Their concern was that the force of the water from the fire hose would depress the touchpad of the fire exit hardware, and the door would unlatch.
A related question that comes up on occasion is whether it’s acceptable to use less-bottom-rod fire exit hardware with an auxiliary fire pin on an egress door. The pin projects when heated to a high temperature, and aligns and secures the doors to help deter the spread of smoke and flames.
Before I answer, take a look at this photo of a door with fire exit hardware after completion of the fire test (this was the intended and expected outcome):
During a fire test, and potentially during a fire, the operable hardware on the door melts away and/or is deactivated by fusible material inside of the product. The latching portion remains, as the door is required to be latched for the entire duration of the test – including the hose-stream portion. But the parts normally used to retract the latch – the lever, touchpad, crossbar, etc. – no longer function in that capacity.
NFPA 101 includes a specific reference to this situation:
126.96.36.199.1 Door leaves shall be arranged to be opened readily from the egress side whenever the building is occupied.
188.8.131.52.2* The requirement of 184.108.40.206.1 shall not apply to door leaves of listed fire door assemblies after exposure to elevated temperature in accordance with the listing, based on laboratory fire test procedures.
A.220.127.116.11.2 Some fire door assemblies are listed for use with fire pins or fusible links that render the door leaf release inoperative upon exposure to elevated temperature during a fire. The door leaf release mechanism is made inoperative where conditions in the vicinity of the door opening become untenable for human occupancy, and such door opening no longer provides a viable egress path.
The International Building Code (IBC) also addresses this:
1010.1.9.3 Locks and latches. Locks and latches shall be permitted to prevent operation of doors where any of the following exist:
5. Fire doors after the minimum elevated temperature has disabled the unlatching mechanism in accordance with listed fire door test procedures.
So to answer the original questions, the hose stream does not actuate the touchpad of the fire exit hardware because the touchpad is no longer able to retract the latch. And the LBR pin is acceptable because the doors and hardware are not operable for egress when the doors reach the temperature at which the pin is projected.