Product Description
LG CW 4040 SF RO membranes qualify for car wash industry and other various commercial applications. LG CW 4040 SF RO membranes, incorporated with innovative Thin Film Nanocomposite (TFN) technology, offer high productivity at ultra-low feed pressure and good salt rejection. The membranes are available in industry standard 4"x40" configuration and can easily fit into existing or new industry RO systems.
Equivalent Products
Oltremare Low4-4040
Axeon HF4-4040, HF5-4040
Hydranautics ESPA4-4040
FilmTec XLE-4040
Desal AK90
These are a popular membrane with window cleaners and car washes however this membrane is designed to be run under set conditions in an engineered reverse osmosis system. Most systems in the window cleaning industry are not run within the manufacturers specifications and as such no warranty can be enforced and are run at the operators own risk.
Things you can do to reduce your chances of damaging the membrane
If running with an engineered RO system designed inline with the membrane manufacturers specifications refer to your installation manual.
Change your pre-filters. It is important to begin a new membrane installation with fresh filters. Blocked or exhausted filters will have a detrimental effect on your membranes performance.
Ensure the membrane housing is clean and sterile before installing a new membrane.
Ensure the membrane is correctly installed (see membrane installation sheet).
The membrane can only be installed one way, any deviation from the correct method will twist the brine seal and stop the membrane operating correctly.
When the membrane is first installed run at tap pressure with the waste fully open. This is to wet out the membrane and flush out any preservative. Never use a pump on a newly installed membrane, it must be wetted out first or it may damage the membrane (hydraulic shock).
After the membrane is wetted out, if you have a pump switch it on now ensuring the waste valve (throttle) is still fully open.
Start with the waste fully open, then close it a little and take a TDS reading. Then close it a little more and take another TDS reading, repeat this procedure. You should observe the inlet pressure increasing and the permeate (product) water TDS decreasing. At some point you will find the at TDS will rise which indicates you've just passed the "sweet spot" so readjust to previous position. The "sweet spot" is the position where the membrane gives you the lowest TDS and balances back pressure with adequate waste water. This is typically at about 80% waste to 20% permeate (product) water if using a single membrane.
NEVER CLOSE THE WASTE WATER VALVE (THROTTLE) OR REDUCE THE WASTE TOO MUCH - IT WILL RUPTURE THE MEMBRANE.
Notes on pump selection.
Ensure the pump you choose not only delivers an adequate pressure but also an adequate flow rate. This will typcially be a multistage centrifugal pump or rotary vane pump.
Ensure the water is delivered at a constant pressure and flow rate. There should be no "pulsing", sudden pressure drops or pressure increases as this will damage the membrane. An example of this is if the pump uses a pressure vessel, this should be avoided or reciprocating pumps.