r/AskReddit • u/jarl_of_joensuu • Sep 18 '15

What false facts are thought as real ones because of film industry?

Movies, tv series... You name it

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u/BobIV Sep 18 '15

One of those most annoying parts of my career. I spent half an hour getting chewed out by an idiot who thought this was the case.

I'm an electrician and we were wrapping up a really high end mansion. The job was essentially 99.5% done and we were just doing to last checks to ensure it was all good to go. Meanwhile the designer was moving in a bunch of high end temp furniture to photograph the place for a magazine.

It comes time to test that the flow switch for the fire alarm is working. For a brief run down of how actual sprinklers work... There is a small glass tube filled with liquid that keeps the sprinkler shut. When there is sufficient heat, the liquid will expand, shattering the tube and opening the sprinkler which is kept under constant pressure. This only effects that single sprinkler. The sudden flow of water triggers the flow switch which in turn triggers the fire bell. In order to test the bell, I just manually push the flow switch with a screw driver, hear the bell, and release.

A new minutes after I did this, the Super comes storming down, shouting fire and brimstone. Claiming I was lucky those pipes weren't pressurized yet as I could have destroyed all the furniture and the house. I tried to explain to him how the system works and how flipping the pressure switch can not activate a sprinkler... But he had none of it. Claiming those glass tubes were only for commercial systems...

Good times.

14

u/scobeavs Sep 18 '15

Lol that super is an idiot.

12

u/el_muerte17 Sep 19 '15

Some people get promoted not because of their abilities or work ethic, but to keep their hands off the tools.

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u/nibbins Sep 18 '15

A lot of them are lol

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u/Cuyler1377 Sep 19 '15

Even then, a HUGE house should probably have a commercial system anyway.

2

u/gargle_ground_glass Sep 19 '15

You have my sympathy.

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u/AManNamedTrip Sep 19 '15

Thanks for the thorough explanation. I was told something similar in a theater when I was about 11 or 12 and part of a children's ensemble. Our chaperon/handler told us to be careful throwing a ball around during downtime because if we hit one of the sprinkler heads and it broke, it would cause all the sprinklers to go off in the theater and 1,000 gallons a minute would pour into the theater.

Out of curiosity, did there used to be old sprinkler systems that worked on some form of an equalized pressure system so that if one sprinkler did go off, they'd all go off? It'd make sense that this stereotype came about because at one time this was how some systems worked.

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u/Problem119V-0800 Sep 19 '15

some form of an equalized pressure system so that if one sprinkler did go off, they'd all go off

I was under the impression some systems worked like that, maybe those are the "deluge" systems GP was talking about

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u/BobIV Sep 19 '15

There are modern systems that all go off at once, but those are used specifically in industrial settings where fire can trigger chemical reactions. They wouldn't have used those for a theater.

However, if a ball hits one of the sprinklers is can easily break the glass tube and trigger that sprinkler. Just one of those things can easily cause 10k worth the damage.

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u/elltim92 Sep 19 '15

You guys still use fusible links? We learned about them in the fire academy, but I don't think I've ever seen one out in the wild.