WET CAK Series User manual

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REMOVE 90% TO 98% OF THE
TOTAL DISSOLVED
SOLIDS AND
100% OF PARTICULATE
CONTAMINANTS

2
INSTALLATION, OPERATION AND MAINTENANCE MANUAL
PLEASE DO NOT DISCARD
THIS MANUAL CONTAINS IMPORTANT INFORMATION WHICH SPECIFICALLY
APPLIES TO THIS UNIT. THIS INFORMATION MAY BE NEEDED AS REFERENCE
DURING ANY FUTURE SERVICING OF THE SYSTEM.
DISCLAIMER AND LIMITATIONS
This manual discloses proprietary information developed by Water Equipment Technologies (WET). This information
is provided for the purpose of operating and maintaining its water purification systems and may not be used for any
other purpose.
It is recommended that this manual be read and understood before performing installation, operation, and
maintenance of the system. The equipment warranty may be voided if instructions are not followed correctly.
The information provided may not cover all possible variations of detail in relation to equipment use. Please contact
the WET Service Department for any technical questions that are not specifically answered in this manual.
The Seller reserves the right to make enhancements or changes that may not be included in the manual. Therefore,
it is understood that the material presented here is subject to change without notice and is for informational purposes
only.
© Copyright 2004 Water Equipment Technologies. All rights reserved.
IMPORTANT USER INFORMATION

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RO MODEL____________________________________
INSTALLED BY_________________________________
TELEPHONE___________________________________
INITIAL STARTUP DATE_________________________
SAFETY NOTES – READ AND UNDERSTAND BEFORE PROCEEDING
The symbols below may be found throughout this manual
Point requiring Special Attention
Don’t Do This!
Safety Check Item
WARNING
♦High Voltage Electricity
◆
Spinning Parts
♦High Pressure Components
◆
Pressurized Water
♦Hazardous Chemicals
◆
Noise
Failure to follow good safety practices and the instructions included in this manual may result in
damage to the unit, its surroundings, personal injury or death.
Please take all possible precautions when working on or around this unit.
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I INITIAL INSPECTION AND HANDLING
On receipt of the unit, note any damage on appropriate shipping documents. File damage claims with the
carrier immediately and NOT with XYLEM WET.
II QUALITY CONTROL
Each RO unit is tested and preserved before shipment to insure quality and performance. This
preservative must be flushed completely from the unit. See the OPERATION section of this manual for
the procedures to do so.
III ELECTRICITY
The CAK-139 and NAK-139 BP require 115 volts, 60 Hz, single phase power. The service line should
have a 15 AMP capacity.
NOTE:220 volt, 50 and 60 Hz units are available as options, motors used on these models are dual
voltage and dual cycle. To verify the electrical specifications, check the “Manufactured By” plate and NOT
the motor plate!
IV INSTALLATION
NOTE:For long term performance with minimum maintenance, check for the following:
1. That ALL chlorine is removed from the feedwater
2. Hardness is removed from the feedwater
3. Iron is removed from the feedwater
4. Fill out the operator’s log sheet completely and return to XYLEM WET to validate warranty.
NOTE:Hardness and iron will foul the membranes and result in a decrease in the amount and quality of
the water produced. The membrane’s performance can be restored by a cleaning procedure (contact
your local representative).
NOTE:If a water softener is used, it should be set to regenerate at night or when the RO unit is not
running.
WARNING:Chlorine must be removed from the feedwater if present. Chlorine will damage the TFC
membrane and VOID THE WARRANTY. If activated carbon is used to remove chlorine, the carbon
MUST be thoroughly rinsed to remove any small carbon fines before the RO unit is operated.
WARNING:If this pump driven reverse osmosis system is not installed and maintained according to all
the instructions provided by the manufacturer, and as a result of not following these instructions by the
installer, the water temperature is allowed to exceed 95 degrees F (35 degrees C), then any consequential
damages that result from components on the equipment failing due to any resulting heat stress are not the
responsibility of the manufacturer and are not covered under the manufacturer’s warranty.

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RO SYSTEM
The purpose of a Reverse Osmosis (RO) water treatment system is to separate dissolved solids from
water. This unit will provide up to 120 gallons of potable water per day.
Incoming water from the supply is pressurized by a booster pump to about 185 psi. The water is forced
against a semi-permeable membrane which passes the water and rejects or blocks particulates and
dissolved solids. The concentrated salts and solids pass out of the unit and flow to drain.
Recovery of an RO unit is the ratio of the pure water created to the feedwater coming into the unit. Design
recovery for this unit is about 80%. This means that in order to produce 120 gallons of pure water, about
150 gallons of feedwater is required, with about 30 gallons of concentrated reject going to drain.
Some things that can reduce water production or upset the recovery are:
•Very high TDS feedwater. Higher levels of contaminants (dissolved solids or organics) require higher
pressures in order to obtain the same product flow. This system has a maximum operating pressure
of 190psig.
•Cold feedwater. Each 1 degree (Centigrade) of supply water change will result in about a 2% change
in water production. If the feedwater temperature drops from 23°C to 18°C, you will get about 10%
less water production.
•Reduced feed pressure. Inlet feed pressure (ie: municipal supply, well pump) will directly affect the
membrane feed pressure. Reducing the membrane feed pressure will reduce the amount of water
produced.
•Clogged inlet filters. As pre-filters age and collect debris, the pressure drop across the filter increases
and flow decreases. At some point, the reduced pressure or flow may actually cause the system to
not operate at all.
•High pH feedwater. At high pH levels, systems are not only less efficient, but the membranes tend to
scale more rapidly. This will also reduce water production.
•Fouled membranes. Scaling, (mineral deposits) and biofouling, (biological growth) either on the
membranes on within the RO unit will reduce production. Both causes may be corrected by prompt
cleaning with a suitable chemical solution. If detected early, system performance may return to
“nearly new” condition.
•Old membranes. As membranes age, water production may decrease or salt passage may increase.
In either case, it is time to buy a new membrane for your system. Nominal life expectancy where
performance at least meets the minimum specifications for the system is about 3 years. The typical
useful life may be as long as 7 or 8 years with care and excellent feedwater quality.
INSTALLATION
1. This RO system requires an adequate water supply, with a line pressure of 40 PSI, within 6
feet of the installation site. This will insure adequate feed pressure to the booster pump after
any filtration.
WARNING:A pressure regulator must be used if the feedwater pressure exceeds a
maximum of 50 PSI.
IMPORTANT:When installing a RO system that utilizes a booster pump in an enclosed
area such as under a kitchen sink, be sure that there is adequate ventilation to dissipate
the heat from the motor. Otherwise the heat buildup can weaken the plastic tubing and
may cause it to burst under pump pressure.

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2. WATER SUPPLY (feed) - Turn off the water supply. Place the 3/8” brass compression valve
in the cold-water line. Attach one end of the 3/8” tubing to the valve using the brass insert and
nylon sleeve provided and attach the other end to the RO unit filter connection marked
“FEED”. See the SYSTEM LAYOUT drawing.
3. DRAIN LINE (concentrate or reject) - Attach the drain saddle tee to the 1-1/2” outside
diameter drain pipe. Drill a 3/8” hole into the pipe. Insert the 1/2” npt x 3/8” compression
fitting into the saddle tee. Attach the 3/8” tube and connect it to the reject fitting. See the
system layout drawing.
4. SERVICE LINE (permeate or product) - Drill a 5/8” hole in the sink top (use a carbon tungsten
drill bit) and attach the chrome faucet. Attach the 1/4” outside diameter tubing from the tee
(marked permeate) to the compression tee on the pressure tank and then to the compression
nut on the bottom of the faucet. See the system layout drawing.
5. ON CHLORINATED WATER - You must rinse the activated carbon cartridges. Do this by
placing a container under the sample port, (see the system layout drawing, item 21) open the
valve 4 or 5 turns and turn on the water supply. Continue this procedure until no more black
color appears in the water.
The unit is factory tested at a 5 to 1 recovery ratio. Rejection of the TDS (Total Dissolved Solids) is at
least 90% at 185 PSI, 78° F and 1000 PPM TDS.
NOTE: If the RO pump pressure exceeds 190 PSI:
1. Remove the acorn nut on the right side of the pump
2. Using a common screwdriver, turn the slotted screw counter-clockwise to decrease pressure.
3. Replace the acorn nut.
WARNING: PUMP WARRANTY IS VOIDED IF THE PRESSURE EXCEEDS 190 PSI
NOTE:Pump model units will automatically shut down when the pressure in the holding tank reaches 40
PSI. Back pressure on the holding tank should not exceed 40 PSI. The RO pump will start automatically
when the product pressure drops below 20 PSI.
V OPERATION
NOTE:On new installations, do not allow any product water to flow into the storage tank until the RO unit
has run for one hour and is thoroughly flushed. This will insure the removal of all traces of the
preservative from the membranes. Do this by shutting down the storage tank valve and opening up the
faucet and let the water run into the drain. Be sure to re-open the storage tank valve for normal operation.
1. After all water hook-ups are complete, turn the water supply on and check for leaks.
2. To start the RO unit, plug in the RO unit using the 3 prong plug in a standard 115 volt outlet or
220 volts if designated for 220 volt power.
3. The unit will not operate unless the feedwater pressure is 20 PSI or higher.
4. The system is equipped with a preset reject water flow controller. No adjustments are
required for setting flow rates.

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VI RECOMMENDED DISINFECTING PROCEDURE
(AFTER INSTALLATION IS COMPLETE)
The storage tank lines going to the faucet must be disinfected to prevent bacteria contamination and
possible odor problems from developing. A dirty prefilter cartridge can also cause odors to develop.
Trace amounts of hydrogen sulfide or methane gas dissolved in the raw water can also cause problems.
(These gaseous compounds will permeate into and through the RO membranes).
The method for proper disinfecting is by using household chlorine bleach and the P6UC4 tube fitting
supplied with the RO unit in the accessory kit: (Refer to Drawing.)
1. Unplug the RO unit. The power must be off before disinfecting.
2. Turn the water supply off (cold water valve).
3. Drain the storage tank.
4. Disconnect the tube from the feedwater fitting going to the pump (step 1).
5. Disconnect the 1/4” tube on the check valve pressure tee switch from the unit (step 2).
6. Remove the 3/8” and 1/4” nuts, grab rings, spacers, and O-rings from the P6UC4 poly fitting.
Put them aside and keep them as spares.
7. Connect the P6UC4 Poly fitting to the ends of the each of the tubing connections removed
(step 3). The tubing connections are long enough to bend together but be careful not to kink
any tubing connections. Connecting these tubes will by-pass the pump during the disinfecting
procedure.
7. Remove both of the carbon cartridges from the housings on the CAK-139 BP or the sediment
filter from the housing on the NAK-139 BP. Add 1 ounce of household chlorine bleach to the
filter sump and place back on the unit. Open the feedwater supply (cold water valve) and the
RO faucet on the sink. Run the water until a strong chlorine bleach smell is noted.
8. Close the RO faucet and fill the pressure tank. Let the tank sit for 30 minutes, allowing the
chlorine to kill any bacteria that might be present. Drain the tank and close the cold-water
valve.
9. Disconnect the P6UC4 Poly fitting and reconnect the tubing to their original connections.
10. Plug in the RO unit.
11. Open the cold-water valve and let the RO water to fill the pressure tank. Drain and flush the
tank several times to remove the chlorine. DO NOT USE THE FIRST 2 TANK-FULLS OF
WATER!!

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VII PREVENTATIVE MAINTENANCE
1. NON-CHLORINATED WATER SUPPLIES, NAK-139 BP (as needed, based on differential
pressure).
Check the sediment prefilter (differential pressure should not exceed 15 PSI).
1) Un-plug the RO unit and turn the feedwater supply off.
2) Remove the filter cartridge from the housing, if it is not soiled, continue with this procedure.
You may have to press the red pressure relief button on the filter housing to relieve the
pressure.
3) Wash the cartridge off under the sink faucet.
4) Return the cartridge to the housing (When inserting the cartridge into the housing, be sure the
O-ring is set inside groove in the sump.)
5) Turn the water supply on and plug the RO unit in.
2. CHLORINATED WATER SUPPLIES, CAK-139 BP (weekly)
The CAK-139 BP utilizes two activated carbon prefilters (GAC-10)
IMPORTANT:The supply water should be checked for chlorine on a weekly basis. This is done by using
the Chlorine Test Kit (item 117) and taking a water sample after the prefilters (see test kit instructions). If
chlorine is present, the activated carbon filters must be changed. Always remember to thoroughly flush
the new carbon filters before putting them into service. This is easily done with the sample port. (See the
SYSTEM LAYOUT drawing)
NOTE:Higher levels of chlorine may require a larger carbon prefilter, if one is needed, contact your local
sales representative.
3. RO PUMP (once every month)
The clamp between the motor and pump should be checked monthly to be sure it is tight. To tighten, use
the tightening screw located on top of the pump shaft. If the clamp is allowed to become loose, the pump
shaft will wear excessively, thus voiding the pump and motor warranty.
PUMP STARVATION
1) The minimum feedwater line pressure should be 40 PSI, and the feedwater line must not
be more than 6 feet from the RO unit.
2) Air should be bled out of the prefilters by depressing the red relief button on top of the
filter with the RO pump turned off.
PUMP PRESSURE (check once a day)
If the pressure exceeds 190 PSI, excessive wear to the pump internals will occur, resulting in
a gradual loss of pressure. Keep the pressure between 130 and 190 PSI.
NOTE:City water main pressure will tend to be higher at night. Monitor the pressure at night and adjust
the RO unit accordingly. On well pumps, check the pressure during the high cycle of the pump.
PUMP CYCLES ON AND OFF (every few seconds)
A defective pump could cause the pump to cycle rapidly on all models. Check for leaks in the
product water line. If there is a pressure tank in-line, be sure it is properly pressurized.

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4. EXCESS TEMPERATURE (Check on start up and once a month)
BLENDING VALVE
Those installations that are using blend valves to mix hot and cold water going to an RO unit
should be check for the maximum temperature of the hot water, especially during the winter.
Also, if the hot water leaks past the blend water valve, it could result in leaking ROMAS and
fittings. Maximum feedwater temperature should be 100 degrees F at 190 PSI, unless a
special heavy duty high-temperature pressure vessel is used.
RECOVERY RATES
Insufficient recovery rates can cause excess heat to build up due to lack of sufficient water
flow through the pump. This heat build-up can also cause leaks to develop and will cause
fouling of the membranes.
VENTILATION
Inadequate ventilation will cause the pump motor to overheat and cut out. It will also cause
leaks due to water temperature build up.
5. RO Membrane Assembly
NOT MAKING ANY WATER
(POSSIBLE REASONS)
Reject ratio is too low
Product water line is blocked
Pressure is too low
TDS is too high
Membrane is fouled
Prefilter is plugged
Storage tank has too much pressure
MAKING TOO MUCH WATER
O-ring by-pass in the RO membrane assembly
Chlorine damage to the membrane
Water temperature increase
Reverse flow through the membrane (causes a rupture in the
membrane)
TDS IS TOO HIGH
O-ring by-pass in the RO membrane assembly
Chlorine damage to the membrane
Membrane is fouled
Ruptured membrane
Increase in the feedwater TDS
High pH in the feedwater

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VIII CLEANING PROCEDURES
WHEN TO CLEAN
Cleaning is required when the quality and/or quantity of water produced falls off by 10% or more from the
original readings at the time of installation. Several conditions can cause a reduction in water quality
and/or water production. The following should be checked first to see if they are causing the problem
before considering cleaning.
•Water pressure change
•Temperature change
•TDS level increase
•Prefilters plugged
•High pH level
WATER PRESSURE
These RO units are designed to operate at pressures between 130 and 190 PSI, any change up or
down; adjustments must be made.
TEMPERATURE
These RO units are tested with water at 25 degrees C and 250 MG/L TDS. Lower water
temperature will result in less water passing through the membrane. Higher water temperature
results in more water passing through the membrane.
As a rule, at a given pressure and TDS level, for each 1-degree change in water temperature the
change in water production is approximately 2%. Thus, if the water temperature is 5 degrees C,
the amount of water produced will be 40% less than at 25 degrees C.
TDS AND REJECTION RATE
As the TDS (total dissolved Solids) level climbs, the amount of water passing through the RO
membrane decreases. If the TDS level has climbed since the time of installation, the unit will
produce less water.
Check the TDS level of the feedwater and compare it with the TDS level at time of installation.
If the TDS levels have climbed, the rejection rate will have to be increased to reduce the TDS
level build up within the membrane.
PREFILTERS
Five Micron (NAK-139 BP)
A dirty prefilter can reduce the amount of water and the pressure going to the RO unit. If the
cartridge appears dirty and/or the differential pressure exceeds 10 PSI it should be cleaned or
replaced (model wars-5). On extremely dirty water, a larger prefilter may be needed.
Activated Carbon (CAK-139 BP)
The activated carbon prefilters are used to reduce volatile organic substances
and chlorine. They should be changed every 3 months or sooner if chlorine is detected after the
activated carbon cartridges.

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Flow Rates - check the product and concentrate flow rates to determine any change from the normal
conditions. Adjust the flows and pressures if necessary to maintain the proper settings. If the pump
pressure is 190 PSI and the recovery rate is too low, the membrane may be fouled and require
cleaning.
Recovery Rates - If the TDS level climbs or an odor develops, measure the amount of water coming
out from the concentrate line, and then do the same for the product water line. The difference in
concentrate to product should be approximately 5 to 1. If the ratio needs to be adjusted, it can be
done by using the adjusting screw on the pump.
NOTE 1 - Under no conditions should you allow the membrane to dry out. Always keep moisture in the
RO membrane assembly, and always keep the ends plugged (Use threaded plugs being careful not to
over tighten, as a cracked end plug may result). If freezing weather conditions exist, drain the water from
the RO membrane assembly and plug the holes before shipping.
NOTE 2 - For the most accurate TDS readings, let the RO unit run for at least 15 minutes.
NOTE 3 - For the warranty to be valid, activated carbon must be used to remove the chlorine from the
water supply. Use a chlorine test kit to determine if any chlorine is in the reject water. If it is, replace the
activated carbon tank or cartridge. If chlorine passes even with a new carbon filter, you need to get a
larger one with greater capacity for chlorine removal.
If you find yourself cleaning the system frequently, a change in the feedwater chemistry may be the cause.
Only a detailed water analysis can determine the likely cause of membrane fouling. Consult your water
retailer or consult the XYLEM WET service department for information and pricing for membrane cleaning
and/or water analysis services.
DO NOT return the RO unit to XYLEM WET without first obtaining Return Merchandise
Authorization(RMA). Company will not be responsible for equipment, supplies, or materials returned
without an RMA. All shipments should be properly insured.

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Part Number 07-MS-1020
Rev 3
October 2018