User Manual

Fire Safety

Building Technologies 049_Archives_and_Libraries_A6

V10271399_a_en.doc

Fire Safety & Security Products 03.2009

…or alternatively they can be operated electrically:

Fig. 28 Electrically operated flap

Of all possible relief flaps, the electrically operated are the less recom-

mended by Siemens. The reliability of gravity and pneumatic flaps is higher

and therefore are preferred.

Important: Some electrically operated flaps open slowly and close very quickly,

but this is the opposite of what is needed for an inert gas discharge!

Possible solution:

– The vent must be timed to be fully open by the time that the system discharges

– The vent must then be timed to remain open for around 50 to 60 seconds

– The vent can then begin to close

– But consider a hold button!!!!

Pressure relief flaps can be installed in 2 different ways:

In Option 1 the flap is in the

room and the overpressure is

released to a duct outside

the protected area.

In Option 2 the duct for pres-

sure release is part of the

protected ambient (included

in volume calculation) and

therefore the duct must have

the same fire and pressure

resistance.

Fig. 29 Pressure relief flaps’ installation

Duct for

pressure

release

Option 1

Option 2

Pressure

Release

flap

Pressure

Release

flap

Constructed with

same fire resistance

class as the

protected room

Overpressure flap

Electrically operated

Overpressure flap