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Chapter 8 • Mounting and connection of pneumatic components
The pipe is connected by carefully inserting the pipe, which has been prepared as described above,
into the 25mm push-in fitting as far as it will go, the insertion depth is approximately 39mm. After
completing these activities, check the correct fit of the pipe.
The pipe system that is connected to the Automatic Purging Unit F-BO-AFE70, including all
components installed in the pipe, such as filters, must be designed such that it withstands the
static overpressure of the connected compressed-air supply with sufficient safety. Although usu-
ally this pressure is never reached during normal operation, this pressure can be reached in case
of severe clogging of the piping. Therefore you absolutely have to contact the suppliers of the
components and make sure that the components meet the requirements.
If the piping and the components connected to it have not been laid professionally or if
components are used which do not withstand the maximum pressure that is available,
severe injuries or damage can occur!
It is recommended that, if possible, the aspirating smoke detector should only be installed in the
course of commissioning the Purging unit, because the pneumatic connection between the Pur-
ging unit and the aspirating smoke detector has to be interrupted when commissioning starts.
8.2.1
Loosening the pipe connection
The Purging unit's connection to a 25mm pipe can also be loosened again by unscrewing the 25mm
push-in fittings.
Make absolutely sure that, before starting this activity, both the supply line of the com-
pressed air as well as the supply voltage are reliably turned off or disconnected and that
they can not be turned on or connected again by mistake.
To unscrew the 25mm push-in fitting you need a suitable wrench for applying a counteracting force
on the hexagon surface of the push-in fitting (wrench size 32mm), as well as a suitable open-end
wrench (or, if necessary, a suitable pair of pliers) for unscrewing the push-in fitting via the octagon
surface (wrench size 35mm). It is not necessary to disassemble the push-in fitting, it only has to be
unscrewed as far as necessary to easily pull out the pipe by hand. When unscrewing the connection,
also make sure that the push-in fitting is not screwed off from the valve body by mistake.
Before the 25mm push-in fitting can be used again after pulling out the pipe, it must be screwed
together again (3Nm torque) and checked for flawless condition of all components.
After finishing the work, make sure that the fit of the push-in fittings is correct and safe.
8.2.2
Use of filters
If it must be expected that the air that is drawn in by the aspirating smoke detector will be particu-
larly dirty, it is recommended that an air filter should be installed between the pipe system and the
Purging unit. Without appropriate prefiltering of the intake air, the accumulation of dust inside the
housing of the Purging unit can cause increased abrasion or even result in the valve piston getting
stuck.
In the event of a fault in the purification of the compressed air, solid or liquid particles in the com-
pressed air which are aspirated again by the aspirating smoke detector after the Purging process has
been carried out, can cause deceptive alarms or result in the rapid contamination of the aspirating
smoke detector. As a precaution it is therefore recommended that a prefilter should be used between
the Purging unit and the aspirating smoke detector.
Many types of aspirating smoke detectors already have prefilters built into their evaluation unit,
therefore a separate prefilter between Purging unit and evaluation unit is not needed.
In any case, filters must comply with the system approval of the aspirating smoke detector used.
Pay attention to the project planning instructions of the manufacturer of the aspirating smoke
detector.
User Manual Series F-BO-AFE70
I56-4252-010
D200-104-00
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