AMIAD - AUSTRALIA & ASIA PACIFIC NEWS - VOLUME 9 - APRIL 2017 April 2017 Vol.9 APAC | Page 4

FREQUENTLY ASKED QUESTIONS
Amiad has a number of technologies, which technology is the right one for me?
Amiad offers screen, disc, media and microfiber technology as shown in the filtration spectrum below. Based on
the filtration degree we can start to reduce the technology options. However, for a 20-micron filtration application,
all four (4) of these technologies overlap and the choice is not that obvious.
These technologies are significantly different and to determine the best technology for your application, we have
to identify and list your assessment criteria (e.g. robustness, reliability, efficiency, footprint, backwash/flush flow
& pressure, cost, operation & maintenance, etc.). Then our application engineers and product managers can,
based on their practical experience and our in-house research & testing, compare these technologies, against
your assessment criteria,
and offer you the choice.
Filtration spectrum
0
1
10
20
50
5000
10,000
Microfiber
Media
In some cases the filtration
requirement (like the
20-micron example above)
is not clearly defined,
hence Amiad Australia
developed a decision-
making framework called
Amiad 4D (or Ami4D for
short) to Discover the real
challenge, Diagnose the
root cause, co-create the
optimum Design and
Deliver measureable
results.
What does minimum sealing pressure mean for air valves?
If the air valve inlet pressure is below atmospheric pressure, the air valve will automatically open to break the
vacuum (normal function), or if the pressure is above the minimum sealing pressure the air valve will not
discharge any water, but if the pressure is between atmospheric pressure and the minimum sealing pressure,
the air valve will leak.
Beware of misleading claims of zero sealing pressure! ISO, EN/BS and AS standards all require the location of the
pressure reading at the air valve inlet, not at the air valve orifice where the pressure is always lower.
Item 5 on the diagram below (from AS4883 and AS4695) indicates the exact location
of the pressure sensing equipment for the relevant tests.
The minimum sealing pressure in the ARI range (measured according the
standards above), varies from 0.2 – 2m, depending on the model.
4 | March/April  2017