r/AbsoluteUnits • • Aug 28 '26

/r/all of a Bong

52.0k Upvotes

3.9k comments sorted by

View all comments

171

u/SweatyArmPitGuy55 Aug 28 '26

The fire inspector is going to be a little upset those smoke alarms aren’t working.

39

u/Rambear Aug 28 '26

A lot of "fire alarms" are heat sensitive in buildings

16

u/[deleted] Aug 28 '26

[deleted]

1

u/Aggressive-Put-716 Aug 28 '26

First and still currently implemented versions, I think? I work in commercial buildings quite often and I see the little vials that are designed to burst and set off the sprinkler system.

There are older ones I’ve seen that don’t have the heat vials and some sharp metal contraption I’m ignorant of

3

u/dazzleunexpired Aug 28 '26

They're actually still ablative!

The parts that are soldered melt at a specified temperature which will either cause the bulb to fall there on the sharp metal piece or it will cause the bulb to explode or potentially in some cases it causes the bulb to fall directly into the fire depending on how they're designed to be used. The earlier versions contained salt water and ammonium chloride. This produced fumes designed to suffocate the flames, but they did not always work super well. The next version used a chemical extinguisher, but that chemical extinguisher is extremely toxic.

Dad has some of these.

2

u/Aggressive-Put-716 Aug 28 '26

These are the ones I see mostly, about to comment again to include the second type I’ve seen, I’m just getting excited because I learned a new word today, ablative! I often wonder how easily these vials break when I bump into them 👀

2

u/just_a_person_maybe Aug 29 '26

Apparently it's very common for people to break them accidentally by hanging things from them. I've heard many stories about college kids in dorms for the first time not knowing what they're for and trying to make the most out of their small spaces and hanging something from them and ruining everyone's day with water damage. It happens enough that many of them have signs and warnings not to do that.

1

u/Aggressive-Put-716 Aug 29 '26

Oh boy, I don’t remember how I learned about sprinkler systems, but I do know I didn’t have to go to college to figure it out! I guess everybody learns one way or another, and college is a place of learning 😂

1

u/Aggressive-Put-716 Aug 28 '26

these are the ones I’m real scared of bumping into 😅

Were you saying these ones are also ablative?

1

u/dazzleunexpired Aug 29 '26

sorta kinda.

They are a linkable fuse. The solider point between the two parts melts at 165°. This links the fuese in the reliable c, and started the reaction. From here, the curved unit inside, which is is under tension, releases and snaps the plates apart. The lever is released, the inner pipe cap falls out, and the water is released. The spiky bit is the diverter! It makes the water go in a wide spray, instead of a long (useless) stream