AMIAD – AUSTRALIA & ASIA PACIFIC NEWS – VOLUME 11 – MARCH 2018 v.1finalAmiad_AU_News_March_2018_high_resolution | Page 4

FAQ'S
What is the filtration area of a disc filter?
The filtration area of a screen filter can be easily
calculated, but this is not the case for disc filters.
To elaborate, with disc filters, filtration occurs while
water is percolating from the outer diameter to the
inner diameter of the element. Colour-coded
polypropylene or nylon discs are grooved on both
sides to a specific micron size, a series of these
discs are then stacked and compressed on a
specifically designed spine. When stacked, the
groove on top runs opposite to the groove below,
creating a filtration element with a statistically
significant series of intersecting grooves, which
trap the solids.
Depending on the micron rating, there are between 18 (in 400 micron discs) to 32 (in 20 micron discs)
stopping points in each track, thus creating the unique in-depth filtration. Therefore, the outside surface
area is not the actual filtration area. The filtration area is along the grooves, which offer multiple
intersection points of varying sizes.
Can I use polymeric automatic control valves in
sea water applications?
Yes, the glass reinforced nylon valves are specifically
designed to resist the elements in the harshest of
environments, both internally, and externally.
The polymeric compound is virtually corrosion-free,
and has numerous other advantages over its metal-
based counterparts, including its resistance to
cavitation which makes it naturally more durable
under these conditions. The polymer based range
of valves are also naturally more suited to more
aggressive liquid chemical compositions, including
higher or lower PH levels, an attribute that widens
its application for mining, municipal, irrigation and
industrial uses as well.
Typical automatic control valve applications for polymeric based automatic control valves, on sea water,
include three-way manual or electric solenoid operated valve open/close using external command
pressure source, or three-way hydraulic pilot valve operated pressure reducing or sustaining using
external command pressure source and diaphragm separator on sense port.
4 | March 2018