USFilter H 3360 User manual

Operation and
Maintenance
Manual
for
H SERIES
(3180, 3240, 3300 & 3360)
Reverse Osmosis Systems
Serial # ________________________
U.S. Filter
10 Technology Drive
Lowell, Massachusetts 01851
Tel: [phone] • Fax: [phone] MANOWNROLH REV H

MANOWNROLH - i -
INDICATIONS
This system has not been configured or labeled for medical device applications, and it has not been
listed with the U.S. Food and Drug Administration. The use of this system in applications requiring
the use of a registered medical device is a violation of federal law.
CONTRAINDICATIONS
There are no absolute contraindications to reverse osmosis water treatment.
CAUTIONS AND WARNINGS
Prior to operating or servicing this device, this manual must be read and understood. If something
is not clear, call for assistance before proceeding. Keep this and other associated manuals for
future reference and for new operators or qualified service personnel.
All electrical work should be performed by a qualified electrician in accordance with the latest
edition of the National Electrical Code, as well as local codes and regulations.
To avoid electrical shock hazard, do not remove covers or panels when power is supplied to the
device. Do not operate the device when covers or panels are removed.
WARNING A faulty pump motor or wiring can be a serious shock hazard if it or
surrounding water are accessible to human contact. To avoid this danger,
DO NOT remove any grounding wire from the system.

MANOWNROLH - ii -
DISCLAIMER STATEMENT
This operation and maintenance manual is intended to be used with the supplier information
provided in the Appendix. These manuals should provide complete and accurate information to
meet your operating and/or service requirements based on the information available at the time of
publication. However, U.S. Filter Corporation (“U.S. Filter”) assumes no responsibility for the
technical content of the supplier literature.
This manual should be read fully and understood before installation, operation or maintenance of
the system is attempted. The information in this manual may not cover all operating details or
variations or provide for all conditions in connection with installation, operation and maintenance.
Should questions arise which are not answered specifically in this manual, contact the U.S. Filter,
Technical Service Department at the phone number provided on the cover of this manual.
U.S. Filter reserves the right to make engineering refinements that may not be reflected in these
manuals. The material in these manuals is for informational purposes and is subject to change
without notice and should not be construed as a commitment by U.S. Filter. U.S. Filter assumes no
responsibility for any errors that may appear in this document. This manual is believed to be
complete and accurate at the time of publication. In no event shall U.S. Filter be liable for incidental
or consequential damages in connection with or arising from the use of this manual.
Copyright 1995 United States Filter Corporation
Printed in the United States of America. All rights reserved.
THIS BOOK OR PARTS THEREOF MAY NOT BE REPRODUCED IN ANY FORM
WITHOUT THE WRITTEN PERMISSION OF THE PUBLISHERS.
PROPRIETARY RIGHTS STATEMENT
This manual discloses information in which U.S. Filter has proprietary rights. Neither receipt nor
possession of this manual confers or transfers any right to the client, and by its retention hereof, the
client acknowledges that it will not reproduce or cause to be reproduced, in whole or in part, any
such information except by written permission from U.S. Filter. The client shall have the right to use
and disclose to its employees the information contained herein for the purpose of operating and
maintaining the U.S. Filter equipment, and for no other purpose.
In the event the content of this manual is altered or section/items are omitted during a reproduction,
in whole or in part, and instructions or definitions within the reproduction result in personal injury to
those who follow the altered instructions, the burden of responsibility for personal injury falls solely
on the party who affects the reproduction.

MANOWNROLH - iii -
MANUAL USER’S GUIDE
This manual describes the procedures necessary to install, operate, and maintain your U.S.
Filter liquid treatment system. Please read this manual carefully before installing and
operating your equipment. The equipment warranty may be voided if installation or
operation instructions are not followed correctly.
Warnings, Cautions, and Notes are used to attract attention to essential or critical
information. Warnings and Cautions will appear before the text associated with them, and
notes can appear either before or after associated text.
WARNING Warnings indicate condition, practices, or procedures which must be
observed to avoid personal injury or fatalities.
CAUTION Cautions indicate a situation that may cause damage or destruction of
equipment or may pose a long term health hazard.
NOTE: Notes are used to add information, state exceptions, and point out areas that
may be of greater interest or importance.
EQUIPMENT SUPPORT
U.S. Filter continually strives to provide safe, efficient, trouble-free equipment using the
optimum technology for your application. If problems should develop, U.S. Filter’s
worldwide network of technical support will be available to provide assistance. For service,
sales, parts, or additional manual copies call your area representative or U.S. Filter,
Technical Service Department at the number provided on the cover of this manual.

TABLE OF CONTENTS
SECTION DESCRIPTION PAGE
MANOWNROLH - iv -
1.0 INTRODUCTION
1.1 System Function.................................................................................... 1-1
1.2 Quality Assurance/Quality Control......................................................... 1-1
1.3 Functions of the System Components................................................... 1-2
2.0 SYSTEM INSTALLATION
2.1 Precautions Before Installation.............................................................. 2-1
2.2 Unpacking.............................................................................................. 2-1
2.3 System Location .................................................................................... 2-1
2.4 Power Requirements ............................................................................. 2-1
2.5 Water Requirements.............................................................................. 2-2
2.6 Permeate Line ....................................................................................... 2-2
2.7 Reservoir (Optional)............................................................................... 2-2
2.8 Accessory Sensors (Pretreatment Interlock and Tank Level)................ 2-2
2.9 Before Power Turn On........................................................................... 2-3
2.10 Installation of Reverse Osmosis Membrane(s)...................................... 2-3
3.0 OPERATING INSTRUCTIONS
3.1 Controls and Indicators.......................................................................... 3-1
3.2 Initial Startup of Reverse Osmosis System ........................................... 3-1
3.3 Initial Flushing of the System................................................................. 3-2
3.4 Normal Operations................................................................................. 3-2
3.5 Prolonged Shutdown (Greater Than 4 Days) ........................................ 3-3
4.0 SYSTEM MAINTENANCE
4.1 General.................................................................................................. 4-1
4.2 Sanitizing the Reverse Osmosis Membrane(s) ..................................... 4-1
4.3 Sanitizing a Storage Reservoir .............................................................. 4-10
4.4 Maintenance Summary Log .................................................................. 4-10

TABLE OF CONTENTS
SECTION DESCRIPTION PAGE
MANOWNROLH - v -
5.0 TROUBLESHOOTING
5.1 System Inoperative ................................................................................ 5-1
5.2 Low System Pressure............................................................................ 5-1
5.3 Low Percent Recovery........................................................................... 5-1
5.4 High Percent Recovery.......................................................................... 5-1
5.5 Low Salt Rejection................................................................................. 5-2
5.6 Low Calcium Rejection .......................................................................... 5-2
5.7 System Keeps Shutting Off.................................................................... 5-2
5.8 System Shutoff, Low Pressure .............................................................. 5-2
5.9 Low Permeate Flow Rate ...................................................................... 5-3
5.10 Motor Overload Shutdown ..................................................................... 5-3
5.11 Controller Malfunction............................................................................ 5-3
6.0 WARRANTY
6.1 General Limited Warranty...................................................................... 6-1
6.2 Water System Limited Warranty ............................................................ 6-1
7.0 APPENDIX 7-1
TABLE # DESCRIPTION PAGE
4-1 Sanitization Times and Concentrations for Polyamide .......................... 4-2
Thin Film Composite Cartridges
4-2 Cleaning Solutions for Polyamide Thin Film.......................................... 4-8
Composite Membranes
4-3 Storage Solutions for Polyamide Thin Film Composite Cartridges........ 4-10

MANOWNROLH INTRODUCTION
U.S. FILTER 1-1
1.0 INTRODUCTION
Congratulations on your selection of this U.S. Filter water purification system. This system is
designed and manufactured to the highest standard of quality and fully tested and inspected by
competent personnel. In order to get maximum performance, we ask you to read all of the
following instructions before installing and operating this system. Any warranty offered will be
void unless directions are followed exactly.
This manual is divided into sections for easy reference. Review this manual thoroughly and
then return to section 2.0 for the step-by-step installation instructions.
If you need technical assistance in operating or maintaining your U.S. Filter unit please call your
local U.S. Filter representative or should you require further assistance call U.S. Filter,
Technical Service Department at the phone number on the cover of this manual.
1.1 SYSTEM FUNCTION
The function of a Reverse Osmosis (RO) system is to separate contaminants from a
water supply by a RO membrane. The system produces purified water that is low in
inorganic salts, organic matter and bacteria. The purified water can be used as a direct
feed to a distribution system or stored in a reservoir.
RO systems operate on the principle of passing water through the membrane under high
pressure. Most of the water passes through the membrane and is purified. A portion of
the water containing the impurities is not passed through the membrane and is rejected
to drain. Prefilters are used in many systems to reduce the amount of particulate
contamination reaching the membrane thus insuring the membrane does not become
clogged.
Please refer to general membrane specifications and System Specifications Sheet in the
Appendix for other parameters important to the operation of the system.
1.2 QUALITY ASSURANCE/QUALITY CONTROL
Quality Assurance and Quality Control are words that mean many things to many
people. All too often they are used as "catch" phrases that sound good but mean little.
At U.S. Filter we have defined these phrases into a series of engineering and
manufacturing practices and control procedures to insure that you, our customer, receive
the finest product available in the world. We will continue to update these practices and
procedures in an effort to improve our systems and to insure that they continue to reflect
state-of-the-art technology and reliability.
Quality assurance is the cornerstone of our quality program. It begins with the selection
and qualification of components and materials. Before vendors are selected, their
products must meet or exceed rigid standards set by our Quality Assurance Department.
From that point, our incoming material inspection insures only reliable components will
be used to manufacture systems. Numerous checks are performed as the system
passes through the manufacturing process. The completed system must pass a series
of tests before release to insure the system meets technical and performance
specifications.
Customer feedback is also an important element of our program. Division heads meet
on a routine basis to review customer feedback and initiate actions that result in process
and product improvements.

INTRODUCTION MANOWNROLH
1-2 U.S. FILTER
Quality audits do not improve products. They do, however, insure that a system meets
or exceeds specifications required for your system.
In the Appendix is a copy of our Quality Control form for your system.
1.3 FUNCTIONS OF THE SYSTEM COMPONENTS
A. Reverse Osmosis Membranes
The prefiltered water enters the RO housing and passes over the surface of an
RO membrane. A portion of the input water continues out of the system through
a reject needle valve. The remainder of the water permeates the membrane and
is directed to an accessory storage reservoir or point of use. Percent conversion
(the ratio of RO product water to feedwater) will vary depending on water quality
and the application. The reject needle valve and the pump throttle valve are
adjusted to provide the proper permeate flux and transmembrane differential
pressure. The permeate flux is also a function of temperature.
B. Reverse Osmosis Pump
The RO system contains a centrifugal pump driven by an AC motor. The pump
motor is turned on and off by a motor starter relay and will not operate when the
pump inlet pressure is less than .69 bar (10 psig). The pump motor starter also
contains an overload relay.
C. Pressure Switch
If the pressure on the pump suction falls below .69 bar (10 psig) a pressure
switch automatically shuts off the pump motor to prevent damage to pump. The
low pressure switch will not be activated with momentary pressure drops of less
than 3 seconds during normal system operation.
If the pump discharge pressure exceeds 20.7 bar (300 psi) a pressure switch
automatically shuts off the pump motor to prevent damage to the pump.
If the system experiences a pressure switch shutdown the condition should be
corrected. The system is manually restored to operation by pressing the reset
button on the control panel.
D. Reject Recirculation (optional)
If the system is provided with the reject recirculation option, it permits part of the
reject water to be returned to the inlet of the high pressure pump. This increases
percent conversion of the system.
E. Auto Flush (optional)
A throttle valve restricts the flow of water through the reject line to maintain
proper reject flow. In the "TANK FEED" and "STANDBY" modes, an optional
solid state timer automatically opens the reject solenoid valve for one minute
every hour, bypassing the throttle valve. The flush time is also programmable to
2 or 4 minutes if the water quality is poor and has a tendency to plug the
membranes necessitating longer flush times. During this time, a high velocity
flush of water sweeps through the matrix of the RO membrane to prevent the
accumulation of scale (carbonate deposits) or other contaminants that tend to
collect on the surface of RO membranes. A new flush cycle begins each time the
system is turned on. The flush cycle is inhibited during the "DIRECT FEED"

MANOWNROLH INTRODUCTION
U.S. FILTER 1-3
mode. To prevent membrane degradation, the system will continue to flush
during the "TANK FEED" mode and during "STANDBY" conditions.
F. Controller (optional)
The controller has the following capabilities:
1. Low pressure shutdown - when the inlet water pressure falls below 1.38
bar (20 psi). There is a 3 second delay to prevent shutdown during
momentary pressure losses.
2. High pressure shutdown - to prevent damage to the pump or elements.
3. High temperature shutdown - to protect the RO membrane from exposure
to damaging temperatures.
4. Low percent rejection alarm - to warn the operator if the product water
quality has gone out of specification.
5. Pump startup delay - there is a ten second delay after turning on the unit
before the pump starts.
6. Automatic flush - the system automatically flushes when the power is
turned on, when the system is placed in "STANDBY", and every hour
during continuous operation ("TANK FEED" mode).
7. Tank full shutdown - will put the system in "STANDBY" when a float
switch in the RO water storage tank detects it is full (optional).
8. Interlock - can link the system with a water softener or other pre-treatment
equipment to provide coordinated startup/shutdown/ regeneration cycles.
9. The inlet solenoid valve is opened automatically when the system is
turned on and closed when the system is put in "STANDBY" or turned off
(the valve delays 5 seconds after the pump stops before closing).
G. Accessories
The RO system can be used to feed a distribution loop, another piece of
equipment directly, or an accessory reservoir. If an accessory reservoir is used,
a level switch is necessary with the "TANK FEED" feature. This accessory is
connected to the control box by wiring the electrical leads to the level switch
connection after removing the shorting wire. Optional terminals (pretreatment
interlock) have been placed in the control box for shutdown by external signals.
Normal operation will resume automatically when the pretreatment regeneration
is completed.
See the System Installation section of this manual for instructions on electrical
connection of the accessories.

MANOWNROLH SYSTEM INSTALLATION
U.S. FILTER 2-1
2.0 SYSTEM INSTALLATION
2.1 PRECAUTIONS BEFORE INSTALLATION
The following are input water source requirements:
A. Inlet pressure is .69 to 6.9 bar (10 to 100 psig) at design feed flow.
B. Temperature is between 2°C (35°F) and 45°C (113°F). Recommended operating
temperature is 25°C (77°F).
C. Free chlorine concentration must be non-detectable on a continuous basis.
If the free chlorine level is detectable, a carbon filter or bisulfite system should be
used as pretreatment to remove chlorine from the feed water entering the RO
unit. Chlorine will cause irreversible damage to the membranes.
D. Langelier saturation index of the reject must be negative at the system's
operating parameters to avoid fouling the membranes.
CAUTION pH must be between 4 and 11. Chlorine must be non-detectable.
NOTE: If input water does not meet the above requirements or there is some doubt,
contact your local U.S. Filter representative or U.S. Filter, Technical Service
Department at the number provided on the cover of this manual for
recommendations.
2.2 UNPACKING
The U.S. Filter RO system is shipped completely assembled. Pressure switches,
gauges, control box, pump, valves and regulators are all pre-mounted on the main frame
and factory set to correct values. Carefully remove from the packing crate to avoid
damage to gauges, RO membranes, etc. Do not drop or handle with excessive
roughness to prevent damage to the electronic components and to prevent damage to
the piping joints.
2.3 SYSTEM LOCATION
A drain, capable of handling the flow of reject water during system flushing, should be
located as close to the system as possible. The reject line should be secured so that
during the high velocity flush the line is not dislodged from the drain.
2.4 POWER REQUIREMENTS
The power requirements for the system are given on the system I.D. plate just below the
controller panel. The system should be connected with a multiconductor, grounded
cable to a disconnect switch box. The switch box should be located within
approximately 10 feet of the system for the convenience of technicians servicing the unit.
The system is provided with a motor starter to permit coordinated over-current protection
as defined by the National Electical Code.
Ground the power cable to the ground connection in the motor starter housing box.

SYSTEM INSTALLATION MANOWNROLH
2-2 U.S. FILTER
Branch circuit conductors supplying the motor shall have an ampacity of not less than
125% of the motor full load current rating as defined by the National Electric Code.
2.5 WATER REQUIREMENTS
The inlet water supply must be adequate to provide the minimum flow requirement
shown in the System Specifications in the Appendix. The inlet line should be sized to
deliver this flow with a minimum pressure of .69 bar (10 psig) at the RO unit. A shut off
valve within 10 feet of the unit and a cleaning connection should be provided. A sample
valve to check feed water quality is also recommended.
2.6 PERMEATE LINE
The permeate line should have sufficient internal diameter to minimize line pressure
drop. It is recommended that a small sample valve be placed in the product line to
facilitate sampling of the permeate water quality. A flow meter is supplied with the unit to
continuously measure the permeate flow rate.
2.7 RESERVOIR (OPTIONAL)
Since the RO system is designed to produce a constant supply of purified water, the RO
membranes must be maintained in an operational state. To retain full effectiveness, a
reservoir is usually required. The reservoir size is a function of spatial location in
relation to system output. Reservoir size selection should be in accordance with this
factor. Your local U.S. Filter representative can supply reservoirs of any desired
capacity as an accessory to the basic RO system.
2.8 ACCESSORY SENSORS (PRETREATMENT INTERLOCK AND TANK LEVEL)
Provisions have been made for shutdown by accessory sensors, provided such sensors
are equivalent to a single pole single throw switch. The shutdown is such that normal
operation will resume automatically when the failure is removed.
A. Remove the cover from the back of the control box to expose the terminal
connections.
B. See the Reverse Osmosis Controller, Operating Instructions in the Appendix to
connect PRETREATMENT INTERLOCK, HIGH TANK LEVEL and MID TANK
LEVEL sensors.
NOTE: If only a high tank level switch is used, a switch should be selected with a built
in “dead band” in order to prevent the RO pump from cycling. Using a switch
without a “dead band” could cause the motor starter to fail and can contribute
to low product water quality.
C. Both the "Pretreatment Interlock" sensor and the “Tank Level” sensor are
normally closed circuits.
D. To connect the accessory, remove the shorting wire and connect a single pole
single throw normally closed switch between the respective terminals. It is
recommended that shielded cable, properly grounded, be used to avoid radio
signal interference with these functions.

MANOWNROLH SYSTEM INSTALLATION
U.S. FILTER 2-3
2.9 BEFORE POWER TURN ON
The controller circuit board should be installed in the controller housing before
connecting electrical power to the unit.
WARNING Personal injury and permanent damage to the controller can result if the
controller is installed with power on the unit.
Once the inlet water is plumbed to the system and the electrical power is connected, the
electrician should verify correct motor rotation. Please refer to the Pump Information
included in the Appendix.
CAUTION Verify that all retaining rings are in place on the RO membrane housings
before turning on the pump.
CAUTION Be sure the product water will not enter the user system during start-up.
The RO system must be operated for four hours to flush out the
preservative solution before connecting to the user system.
2.10 INSTALLATION OF REVERSE OSMOSIS MEMBRANE(S)
A. U.S. Filter RO units are normally shipped with the membranes installed and
preserved in sodium bisulfite solution. However, should the need arise, the
following procedure may be followed to install membranes.
B. See the Appendix for a diagram of the individual components of the membrane
assembly. Before sliding the membranes into the fiberglass housing, lightly
lubricate the chevron seal and o-rings with glycerin. Be careful not to damage
the o-rings when inserting.
C. Load the RO membrane housings from the direction in which the feed will enter,
inserting the end without an o-ring first. They should be removed from the
opposite end.
WARNING Never engage or disengage retaining rings without wearing safety
glasses.
D. Place an end cap into the RO housing end opposite from loading end. Hoses
should be connected to end cap before insertion into the housing. Secure the
end cap with the retaining ring. Snap ring pliers are very helpful for this
operation.
E. Install the adapter and end plug on the feed end and secure it with a retaining
ring.
CAUTION Never allow the RO membrane to dry out once it has been wet, or
irreversible damage will result.

MANOWNROLH OPERATING INSTRUCTIONS
U.S. FILTER 3-1
3.0 OPERATING INSTRUCTIONS
3.1 CONTROLS AND INDICATORS
The controls and indicators used in the operation of the system are outlined in the
Appendix. The operator must be thoroughly familiar with the controls and their
respective functions for proper operation and in order to maintain the quality of the
permeate and eliminate unnecessary shutdowns.
3.2 INITIAL STARTUP OF REVERSE OSMOSIS SYSTEM
A. The operator should verify that appropriate pretreatment is in place and operating
satisfactorily, otherwise the RO membranes will become fouled rapidly.
B. Make all water, electrical and drain connections according to installation
instructions.
C. Be sure that the controller is turned off.
D. Turn on the inlet water and the electrical power at the remote disconnect. Direct
product water to the sewer until proper operation of the system is verified and
product quality is known to be within specifications.
CAUTION Check to verify all RO housing retaining rings are in place and engaged.
E. Close the reject recirculation valve.
F. Open the reject valve completely.
G. Open the pump throttle valve one (1) turn.
H. Turn the on/off switch to "ON".
I. Check to verify the pump motor is rotating in the proper direction. Please refer to
the Pump Information in the Appendix for information concerning motor rotation
and any other electrical connections.
CAUTION Do not run the motor for more than 30 seconds backwards or irreversible
pump damage may result.
J. If your RO system is equipped with the Reject Recirculation Option, set the reject
recirculation flow to zero, but DO NOT exceed pressure to membrane limits.
Open the reject valve further if necessary to avoid over pressuring the system.
CAUTION Do not use reject recirculation option for the first 24 hours of operation to
avoid recirculating the preservative chemicals.
K. Check for plumbing leaks and make appropriate repairs as necessary. All
systems are leak checked at the factory but vibration during transit can cause
new leaks to develop.

OPERATING INSTRUCTIONS MANOWNROLH
3-2 U.S. FILTER
3.3 INITIAL FLUSHING OF THE SYSTEM
Since the RO membrane is shipped moist with sodium bisulfite preservative solution,
initial flushing of the system is required. Before operating a new system, and also after a
replacement of an RO membrane, perform the following steps:
A. Place the outlet of the permeate at a convenient drain.
B. Turn on the input water and the system pump (as outlined in Operating
Instructions, Initial Startup of the Reverse Osmosis System section of this
manual) and let the system run for 4 hours with the reject valve completely open.
Adjust the pump discharge valve so that the membrane feed pressure is
approximately 5.2 bar (75 psi). This will flush residual bisulfite solution and any
particulate impurities from the membranes, housings and plumbing of the
system.
C. Permeate quality will increase slowly for 1 hour. Monitor the inlet quality vs. the
permeate quality.
NOTE: The system should have better than 90% rejection within 2 hours as the
membranes equilibrate. If the permeate quality does not improve, refer to the
Troubleshooting section of this manual.
D. After flushing, turn off the system and reconnect the permeate line. The system is
now ready to be put into a normal operating mode.
3.4 NORMAL OPERATIONS
It is best to operate the RO system continuously to avoid membrane fouling; however,
the automated controls provide periodic flushing of the system. Rather than produce
water at a maximum capacity then shutdown the system, it would be better practice to
balance the product water rate with demand. This is achieved by increasing or
decreasing the membrane feed pressure with the pump discharge throttle valve.
A. Initiate operation by turning on/off switch to "ON".
B. After waiting for completion of the flush cycle, which is initiated each time the unit
is put into operation, adjust the reject control valve and/or recirculation flows to
give slightly more reject flow than the minimum indicated on the System
Specifications sheet in the Appendix. This will assure that inorganic salts will be
removed from the reject side of the membranes in concentrations low enough to
avoid fouling.
C. If product water is set to slightly exceed demand the unit will automatically shut
down when the product water storage tank is full.
D. Check the conductivity of the inlet and product water to verify the unit is operating
properly.
E. Enter the operating data on the log sheet (sample in Appendix). Check the unit
at least daily and follow the Maintenance Summary section, logging in the
operating data as prescribed.

MANOWNROLH OPERATING INSTRUCTIONS
U.S. FILTER 3-3
3.5 PROLONGED SHUTDOWN (GREATER THAN 4 DAYS)
When the system is going to be inactive for more than 4 days (not in a "STAND-BY"
mode), perform the following steps:
A. Turn off the input water source.
Bisulfite Sanitization (4 days to 1 month shutdown)
Drain water from the system and pump in a 0.5% sodium bisulfite solution
to prevent biological growth in the elements.
or
Formaldehyde Sanitization (shutdowns exceeding 1 month)
Drain water from the system and pump in a solution of 3% formaldehyde
to prevent biological growth and kill residual bacteria.
B. Remove the prefilter cartridges and discard. Clean the prefilter housing, leaving
the cleaned components to dry during the shutdown period.
C. Turn off the input water and electrical power until the system is to be placed into
operation again.
D. To resume system operation, first drain the solution from the RO housings, install
new prefilter cartridges, disconnect the permeate line from the reservoir and run
to drain. Then turn on the input water and start the system, run the permeate
water to drain for 4 hours to flush the system. The product water should be
analyzed with the Fast Formalert or other formaldehyde test kit until detection
limits are reached. Reattach the permeate line and start the system as outlined
in the Operating Instructions, Normal Operations section of this manual.

MANOWNROLH SYSTEM MAINTENANCE
U.S. FILTER 4-1
4.0 SYSTEM MAINTENANCE
4.1 GENERAL
Routine customer maintenance procedures consists of periodic replacement of the RO
membranes and the filter cartridges in the prefilter unit and sanitization of the RO
membranes and the storage reservoir. Cleaning/sanitizing is recommended every four
to eight weeks. The RO membranes should have a life of about 3 years if used properly.
In addition, the system's external surface should be kept clean by occasionally wiping
down all surfaces with a dust-free cloth and visually checking for cracked glass on
gauges, loose fittings, and broken or missing hardware.
Whenever prefilters or RO membranes are replaced, inspect the serviceability of the
o-ring seals prior to assembly. Inspect o-rings for signs of deterioration or cracking, and
replace as required. It helps to lubricate o-rings with silicone grease before reassembly.
4.2 SANITIZING THE REVERSE OSMOSIS MEMBRANE(S)
Periodically, the RO Systems may require sanitization in order to maintain the
performance of the RO membrane, and to ensure a low bacterial count in the product
water. How frequently the system is sanitized depends on the quality of the water
needed for your particular application. Monitor bacterial levels in the feed and
permeates as needed. When bacterial levels increase above an acceptable level for the
application, sanitize the system.
The choice of the sanitizing agent depends on its compatibility with the polyamide thin
film composite RO cartridges and system components, and the agent’s effectiveness as
a sanitant. Three commonly used sanitants are formaldehyde, hydrogen peroxide and
peracetic acid.
CAUTION Chlorine is not compatible with thin film composite cartridges, and must
not be used to sanitize them.
A. Different Sanitizing Agents
CAUTION When using formaldehyde to sanitize thin film composite cartridges, the
cartridges must have been in use for 24 hours prior to sanitization, or a
severe loss in flow rate may occur.
1. Formaldehyde
Formaldehyde is one of the most effective agents used for sanitization. It
is compatible with most materials, is highly active as a biocide over a
relatively wide pH range, and easily penetrates the RO membrane, thus
ensuring that the downstream side of the filter is sanitized. But,
formaldehyde is difficult to flush from the system after sanitization, has an
objectionable odor, and causes irritation to the eyes and nasal passages.
In addition, formaldehyde is a suspected carcinogen. Even so,
formaldehyde is commonly used for sanitizing RO cartridges.
Formaldehyde, in solution, is purchased as formalin, which is a 37%
solution of the formaldehyde gas stabilized with methanol.

SYSTEM MAINTENANCE MANOWNROLH
4-2 U.S. FILTER
2. Hydrogen Peroxide
Advantages of using hydrogen peroxide are that it has no toxic vapors, is
biodegradable, is easily disposable, has good biocidal activity, and breaks
down into oxygen and water, which does not harm the environment.
Because of these qualities, operators can be assured that they are not
handling toxic materials.
3. Peracetic Acid
Advantages of using peracetic acid are that it has no toxic vapors, is
biodegradable, easily disposable, and has good biocidal activity.
Because of these qualities, operators can be assured that they are not
handling toxic materials. Peracetic acid decomposes into oxygen, water,
and acetic acid, which does not harm the environment. Several peracetic
acid solutions are commercially available, including; Minncare and
Renalin Dialyzer Reprocessing Concentrate, both products of Minntech
Corporation, and P3-Oxonia Active, a product of Henkel Corporation. For
ordering information call the number provided on the cover of this manual.
B. Selecting a Sanitant
Table 4-1 lists the type and concentration of sanitizing agent that should be used
for polyamide thin film composite cartridges, as well as the minimum contact time
for sanitization.
Sanitant Sanitant Concentration Sanitant Contact Time
Formaldehyde * 2-3% 30-60 minutes
Hydrogen Peroxide ** up to 2000 ppm (0.2%) 30-60 minutes
Peracetic Acid ** up to 2000 ppm (0.2%) 30-60 minutes
Table 4-1: Sanitization Times and Concentrations for Polyamide Thin Film Composite
Cartridges.
* When using formaldehyde to sanitize thin film composite cartridges, the cartridges must
have been in use for 24 hours prior to sanitization.
** When using hydrogen peroxide or peracetic acid with thin film composite membranes, the
temperature should not exceed 25°C (77°F). Also, the presence of iron or heavy metals
can cause membrane degradation. Clean the membranes first if iron is present in the feed
water.
C. Testing for Residual Sanitant
After flushing the sanitant from the RO system, the permeate water should be
checked for residual levels of sanitizing agent before the system is placed back

MANOWNROLH SYSTEM MAINTENANCE
U.S. FILTER 4-3
on line. Use the following guidelines to determine if the system is clear of
residual sanitizing agents.
1. Formaldehyde
The product water should be analyzed with the Fast Formalert or other
formaldehyde test kit until detection limits are reached.
2. Hydrogen Peroxide
The product water should be analyzed with a hydrogen peroxide test kit.
3. Peracetic Acid
The product water should be analyzed with the Minncare Residual Test
Strip or other peracetic acid test kit. For ordering information call the
number provided on the cover of this manual.
D. Methods of Sanitization
Sanitization is most effective when the RO system is operating at normal
pressure and flows. This allows the maximum amount of sanitant to penetrate
through the membrane, ensuring adequate sanitization of the product side of the
system. Three methods of sanitization may be used: Continuous Injection,
Recirculation and Static Soak.
1. Continuous Injection Method
In this method of sanitization, an accessory chemical feed system injects
concentrated sanitant into the feed line while the RO is operating at
normal flows and pressure. Both the product and reject streams are sent
directly to drain.
The continuous injection method is most typically used to sanitize with
hydrogen peroxide. It is not practical for formaldehyde sanitization
because the dilution ratio used for formaldehyde (1:10 to 1:20) would
require the use of a very large chemical feed pump. The advantages of
the continuous injection method are minimal chemical handling and
minimal dead legs in the system piping. One disadvantage is the
relatively high chemical consumption.
The basic steps for continuous injection sanitization are as follows:
a. Reject and product lines from the RO are diverted to drain.
b. The system is placed in the normal operating mode.
c. An accessory chemical feed system is turned on to inject
concentrated sanitant into the feed water. The sanitant is diluted
by the feed water to the recommended concentration.
d. The system is left running in the normal operating mode for 30 to
60 minutes.
e. The chemical feed pump and the RO system are shut down, and
the sanitant solution is allowed to sit in the system (optional).
f. The RO is run in the normal operating mode with the product
diverted to drain until all residual sanitization chemical is flushed
from the system.

SYSTEM MAINTENANCE MANOWNROLH
4-4 U.S. FILTER
2. Recirculation Method
This method requires an accessory tank and booster pump. A sanitant
solution is prepared in the tank and fed to the RO system via the booster
pump. The product and reject streams are diverted to the tank and the
sanitant is recirculated through the system for a period of time.
The advantages of the recirculation method of sanitization are minimal
usage of chemical, and ease in obtaining the proper sanitant
concentration. In addition, the accessory tank and booster pump may
also be used for system cleaning.
The following steps provide a general guideline for the recirculation
method of sanitization.
a. A batch of sanitant, typically 40 to 100 gallons (160 to 400 liters),
is prepared in the tank by diluting sanitization chemical with water.
b. The product and reject lines are diverted to the tank.
c. The feed to the RO is connected to the outlet of a booster pump,
which pumps sanitant out of the tank.
d. The booster pump is turned on and the RO is run in the normal
operating mode for 30 to 60 minutes.
CAUTION Monitor the solution temperature during recirculation. Do not allow the
temperature to exceed 25°C.
e. The booster pump and the RO system are shut down and the
sanitant is allowed to sit in the system (optional).
f. The RO is switched back to the normal feed source and run in the
normal operating mode with the product diverted to drain until all
residual sanitization chemical is flushed from the system.
g. The tank and booster pump are drained and flushed with clean
water.
3. Static Soak Method
This sanitization method may be used in combination with either
recirculation or continuous injection sanitization for heavily bio-fouled
systems. In this method, sanitant is introduced into the system and then
the system is shut down. The membranes are allowed to soak in the
sanitant solution for a period of time ranging from as little as 30 minutes
up to several days (check with U.S. Filter, Technical Service Department
at the number provided on the cover of this manual for recommended
maximum soak time).
Occasionally a system must be sanitized without a chemical feed system
or an accessory tank and booster pump. In this case it is possible to
perform a static soak sanitization by placing concentrated sanitant in the
RO system prefilter housing, or by manually injecting it into the feed line.
The RO pump is then turned on briefly to flush the sanitant into the
system. The system is then shut down so that the cartridges may soak in
the sanitant solution. The drawback of this method of introducing sanitant
is the sanitization chemical is not evenly distributed throughout the RO

MANOWNROLH SYSTEM MAINTENANCE
U.S. FILTER 4-5
system. Localized areas of high sanitant concentration could degrade the
RO membranes. Also, the length of time that the RO pump is turned on
will be different with each model of RO system and the means used to
introduce the sanitant.
CAUTION Do not use the static soak method of sanitization with any chemical other
than formaldehyde.
E. Cleaning the System
When the RO systems are properly operated, they do not require frequent
cleaning. In time, however, the RO membrane cartridges can become fouled to
a point where system performance is adversely affected, resulting in diminished
product output or salt rejection. When the product flow rate drops by 10% and/or
the salt content in the product water rises noticeable, this may indicate fouling of
the cartridge membrane. However, other factors such as temperature
decreases, or malfunctioning pretreatment systems, pressure controls and
pumps may also cause these conditions. It is important to rule out these factors
before cleaning the system.
Clean the cartridges if the system performance (based on flow rate or salt
rejection) decreases because of membrane fouling. An increase in the feed to
reject differential pressure also indicates that cleaning is needed. Membrane
foulants include colloidal materials such as aluminum and silica compounds,
precipitated metal hydroxides of iron and manganese, biological films, and
calcium or magnesium carbonate scale.
The type of cleaning solutions (See Table 4-2), and the sequence in which they
are used, depends on the type of foulant present (organic compounds, metal
hydroxides, Ca/Mg carbonates, etc.). The need for frequent cleaning (twice a
week or more), may indicate that pretreatment is inadequate. This section
includes general guidelines for developing a cleaning procedure for your
particular application.
F. Effects of Foulants on RO System Performance
1. Colloidal fouling
Causes product flow rate to decrease, and salt passage to increase,
usually in that order. RO systems that operate on high SDI feed water
are prone to colloidal fouling.
2. Metal hydroxide (iron, manganese)
Causes a significant and rapid decrease in the product flow rate, and an
increase in salt passage.
3. Biological fouling
Causes a biofilm to form on the membrane surface. This biofilm inhibits
the membrane’s ability to reject salt, and therefore salt passage
increases. The product flow rate may also decrease, but not necessarily
at a rapid rate.
4. Scaling
Causes a decrease in the product flow rate and an increase in salt
passage.