Davey Aquashield MAX Packaged Ultra Violet Water Treatment System - Manual (Page 13)

13
PRE-TREATMENT (FILTRATION)
Prefiltration is usually required to ensure that particulate matter does not
shield micro-organisms from the UV light. Sand filtration or 20 micron
cartridge filtration is the usual minimum, this is provided in Stage 1 filtration.
In some cases, particularly with surface water, finer filtration may be
necessary, or if cysts like giardia or cryptosporidium may be present. In
this case 1 micron filtration is required, as provided in Stage 2 filtration.
Temperature Rating
Maximum 50 o c - minimum 8 o c
Sediment Cartridge Filter Life
Once the housing is properly installed, a reduction in flow/pressure (to
such an extent as to cause inconvenience) will indicate when the cartridge
is becoming clogged and needs replacing/cleaning. Sediment cartridges
should be replaced/cleaned/sanitised when the water flow has been
noticeably reduced/or after 3-6 months - whichever comes first (this is for
hygiene reasons).
Changing the Filter Cartridge
1. Turn off the valve to stop the flow of water.
2. release the pressure by opening a tap downstream, or use the
pressure relief valve that is available in the lid of some filter housings.
3. unscrew the bottom housing from the lid and pull out the used cartridge
and discard or wash. The inside of the filter housing and the lid should
be checked for cleanliness - they will usually need to be cleaned or
sanitised - use hot water and dishwashing liquid, thoroughly scrub all
surfaces and then rinse.
4. check that the oring is in position in the top of the housing base,
lubricate with a coating of white petroleum jelly (Vaseline), place the
Caution: The housing must be protected against freezing. Failure to do so
may result in cracking of the housing and water leakage.
NOTE: Actual filtration/purification life of cartridge can vary with the
condition of incoming water.
NOTE: Clean filter Stage 1 once a pressure drop of 100 to 150kPa from
clean, or between Stages 1 and 2.
WARNING: CAREFULLY AND GENTLY TIGHTEN WITH HOUSING SPANNER
as the bowl should only be tightened enough to avoid water leaking
during operation.
WARNING: If the water system is not going to be used for extended
periods, the cartridge should be removed from the housing and replaced
with a new or cleaned cartridge when the system is used again.