Re: Aero Tubing

[cfrancis558@xxxxxxxxx]

On Thursday, March 12, 1998 4:00:00 AM UTC-4, PWildemann wrote:
> Does anyone remember this?? Due to economic reasons a client would like t=
o
> keep this in service!! Is it still supported  by a fire company and by wh=
om ??
>=20
> Phil

Yes, a little late but better than never. Aerotubing, connected copper tubi=
ng through out a building and the buildings heat would effect the pressure =
inside the tubing. This was regulated at a the head by inside a device that=
 had actual pumas stone (old volcanic rock) that allowed for the rate of ri=
sing temperature during the day and evening. But if a fire actually happene=
d the heat would increase the pressure inside the head that caused a cam to=
 lift and therefore release a code wheel that would tap out the code onto a=
 McCullough circuit which would be received at the central station who woul=
d respond accordingly. I used to inspect these devices with a brass pump to=
 inject air into the tubing insuring had no leaks by triggering it. Pressur=
e allowance for passing heat etc. was set using what was called a manometer=
. Trouble shooting these were a major pain but outside of an old ADT 6121 p=
ressure switch on sprinkler risers these were excellent fire alarm devices.=
 I remember the fire department at one place I inspected all scratching the=
ir heads trying to figure them out... I worked for ADT as a fire alarm insp=
ector back in "the day" lol...