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TECHNICAL
<< Continued from page 69
Figure 5: Backflow conditions.
Diagram 6: An example of the
installation of an RPZ valve.
reduce supply pressure. We should all be concerned
with the efficient use of our water resources.
This group of fittings is termed ‘the protection unit’.
The point in the system at which the protection unit is
installed is called the protection point. The protection
point is usually located on the service pipe serving
a building before any tee-off from the service pipe,
downstream of the municipal water meter but on the
erf premises. In larger, more complex installations,
depending on the nature of activity and processes
April 2018 Volume 24 I Number 2
taking place, additional protection points may be
required to protect the overall on-site water reticulation
system as well.
The protection unit must be installed with the discharge
port of the RPZ at 30cm above a suitable drain point.
AN INTERESTING POINT
It’s amazing sometimes what answers you get
when the question is asked what the purpose of a
vacuum breaker is, as installed on a SANS 10254
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