On 04/10/2020 13:44, GB wrote:
On 04/10/2020 12:58, Chris Hogg wrote:
On Sun, 4 Oct 2020 12:34:51 +0100, nightjar wrote:

On 04/10/2020 12:15, JohnP wrote:
A school has just gone up in flames in my area. Usual photos of it
burning
inside whilst water is put on the outside. Usual cries for
sprinklers - but
these can be vandalised and could cause problems.

I know about dry risers - usually to Landing Hose Unions - but what
about a
simple array of pipes in the roof space with open nozzles. In the
event of
a fire then the Fire Engine hooks up and dowses the fire from the
inside
using the fixed nozzles - no need to enter the building. Notre Dame
would
have possibly been saved if such a simple system was in place.

Any thoughts? It seems a compromise to a full sprinkler system but
has the
advantage of not being automatic and able to flood the building.


Unlike a sprinkler system, which releases water only in the vicinity of
the fire, that would release water throughout the building. Fine if the
whole building is on fire, but it could result in unnecessary water
damage if the fire were only localised.

There are dry sprinkler systems. They contain compressed air or
nitrogen, but they still need a detector head to activate. That releases
the gas which, in turn, activates a valve that allows water to enter the
system.

IIRC large electrical installations such as large switch rooms in
basements etc have CO2 cylinders installed and ready to be discharged
in case of fire, thereby depriving the fire of oxygen but not
electrocuting anyone by throwing water around. But there's the danger
of suffocation if the system goes off and there's someone trapped
nearby.


I had an MRI scan recently, and the room had a very, very heavy steel
door that appeared air tight. I assume that was to protect the rest of
the building if the helium boiled?



https://www.webmd.com/a-to-z-guides/...-of-its-kind#1

"Accompanying nurse from the wards attempted to bring an unchecked
oxygen cylinder into the magnet room despite being briefed beforehand in
relation to safety around the MRI and specifically the oxygen cylinder.
After being stopped by radiographers from taking cylinder any closer to
the machine and potentially causing serious harm to both patient and
equipment the nurse was unapologetic and did not seem to understand the
gravity of the situation despite all the prior warnings." :-

https://www.google.co.uk/url?sa=t&rc...hyTEdneFyr Yc