Nortec ME Direct Feed Installation - Manual (Page 43)

43 Appendix
5 Appendix
5.1 Inlet water quality requirements
Nortec Plc recommends that the Nortec ME must be connected to a clean, wholesome (drinking water
quality) mains water supply. For areas of hard water and to minimise scale build up the water supply
may be treated by a reverse osmosis system (RO).
Reverse Osmosis
For Nortec ME systems supplied with RO water it is recommended that the system is operated within the
following parameters. The use of RO water fed tanks and reservoirs is only permitted as part of a man-
aged and hygiene monitored water system and should form part of the water system risk assessment.
System Conductivity
Nortec ME Direct Feed > 30 μS cm-1 at 20 °C (68 °F)
Other Water Supplies
There is a growing demand to utilise sustainable water sources to help overcome scarcity challenges
and recycle water. It is possible to use high-quality, treated effluent for non-wholesome applications. The
following gives guidance on reclaimed water quality that may be acceptable for use within the Nortec ME.
“Effluent treated water”, must be treated by an appropriate water treatment method and risk assessed to
ensure it is safe and suitable for use in the Nortec ME unit. It is the responsibility of the user to ensure
that the water supply system is part of a managed, hygiene monitored water system, risk assessed and
complies with the local regulations and bylaws.
Below are example water conditions that would allow a Nortec ME to operate within specification.
Parameter Content in supply water Concern
Temperature < 20 °C (68 °F) Warm water favours growth of bacteria
Aluminium - No specific concerns
Ammonium < 0.50 mg/l Odour passed to air
Calcium < 300 mg/l Scale formation
Chloride < 300 mg/l Corrosion of stainless steel
Colour None Not directly a concern
Copper < 1 mg/l Deposits and corrosion stimulation
Conductivity < 650 μS cm-1 at 20°C (68 °F) Total hardness and scale formation.
pH 6.5 to 9.5 Acid or Alkali damage to equipment.
Iron < 0.5 mg/l
Deposit formation on oxidation and a critical support
role in Legionella growth.
Manganese < 0.1 mg/l Deposit formation
Nitrate - No specific concerns
Nitrite - No specific concerns
Odour Acceptable to users Smell passed to air
Sulphate < 250 mg/l No specific comments
Sodium - No specific concerns