Page 295 - CITS - Electronic Mechanic - TT - 2024

ELECTRONICS MECHANIC - CITS

A second-stage carbon filter, which removes chemicals like chlorine (most city water utilities provide chlorinated
water supplies).
A carbon polishing filter, which is installed after the RO membrane and gives water a final polish.

Reverse Osmosis Membrane:
The RO membrane, or semipermeable membrane, is a key part of any RO system.
Semipermeable membranes use membrane separation to remove virtually all inorganic and organic substances,
including chemicals, metals, microorganisms, minerals, and salts.
RO membranes are usually the third stage in an RO unit and have a 2-year average lifespan.
Other Parts:
Water Supply Connector:

The water supply adapter or connector connects the under-sink or whole house cold water supply to the RO sys-
tem. The adapter should make it possible to connect the RO unit to different-sized water supply lines.
Shut-Off Valve:
A shut-off valve is used in an RO system that has a water chamber or storage tank.

The role of the shut-off valve is to prevent unnecessary draining when the tank is full.
Check Valve:
Again, in RO systems with a water tank, the check valve is needed to prevent high-pressure purified water from
back-flowing into the RO system, potentially damaging the membrane.
The check valve is usually installed directly after (downstream of) the semipermeable membrane.
Drinking Water Faucet:
Most under-sink RO systems come with their own dedicated faucet.
This faucet is lead-free and free from any other metals and substances that could leach back into RO purified
water, which is empty of impurities and more susceptible to recontamination.

Optional Components:
There are a few components of a reverse osmosis system that are sold as optional add-ons. It’s often worth pay-
ing the extra cost for these components.
Water Storage Tank:

RO water storage tanks aren’t technically an optional component – if you buy a tank-based RO system, you will
need to install the tank.
Remineralization Filter:

Many RO water filters now come with an optional remineralization filter. Reverse osmosis removes up to 99.99%
of all dissolved solids in water, including healthy minerals and salts like calcium, magnesium, zinc, sodium, and
potassium.
Pressure Booster Pump:
A pressure booster pump is an optional add-on for homes that don’t have a high enough feed pressure to install
a reverse osmosis water filter system.
The ideal water pressure for a reverse osmosis system is 60 PSI, and water pressure below 40 PSI won’t provide
enough force to send water through the numerous filter stages. A pressure booster pump increases water pressure
to a suitable level for RO performance.
Pressure Regulator:
On the other end, high water pressure could damage the pre-filter housings in an RO system, and a pressure
regulator is used to protect these housings from water hammer.

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CITS : E & H - Electronics Mechanic - Lesson 160 - 179