Page 104 - FreeStyler® Maintenance Manual

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MAINTENANCE

Chapter 3 General Repairs

Spot Free (RO)

Membrane
1) RO Membranes are housed in the long cylinder, or housing. The RO membranes take tap water
and separate it into pure and reject (waste) water. After an RO is in operation for some time, many
things can cause the membranes to function poorly.
2) RO membranes are sensitive to temperature. As the water temperature drops the RO productivity
drops. Evidence of this sensitivity is a drop in water production from summer to winter.
3) Since RO membranes are separating pure water from wastewater, they are susceptible to
membrane fouling. This fouling can occur from mineral scaling or organics. These conditions are
evidenced by loss of product quality (prolonged indication of low quality) or low product flow
(reduced flow on the meter or the tank takes too long to fill). Most of these problems can be
avoided by regular pre-filter changes and cleaning of water stabilizer.
An early indication of membrane fouling is an increase in DELTA pressure, the difference between
pump and membrane pressure. For example, a 3000 GPD system should run at 180 PSI pump
pressure and 140 PSI membrane pressure for a difference, or DELTA pressure, of 40 PSI or about
22%. If the system is in run mode and the DELTA is more than 30%, attempt to readjust the
pressures using the needle and gate valves.
Always maintain the reject flow shown for your system. Do not exceed the pump pressure shown
for your system. If it is not possible to get back below a 25% DELTA, clean the membrane as
explained below. These changes are easier to monitor if regular product flow and pressure
readings are taken at weekly intervals.
4) Some conditions are irreversible such as CHLORINE ATTACK. The normal chlorine levels found in
municipal drinking water supplies can destroy the membrane surface. The only way chlorine can
be controlled is by regular changes of the carbon filter. Carbon removes chlorine from the water.

RO Membrane and Housing

3-40 Belanger, Inc.® * PO BOX 5470 * Northville, MI 48167-5470 * Ph (248) 349-7010 * Fax (248) 380-9681 1MANUL222