Watts R4X40 User manual

REVERSE OSMOSIS
INSTALLATION AND OPERATION MANUAL
Model R4X40

IMPORTANT
Please read the entire manual before proceeding with the installation and startup:
Do not use where the water is microbiologically unsafe.
Always turn off the unit, shut off the feed water, and disconnect the electrical power when
working on the unit.
Never allow the pump to run dry.
Never start the pump with the reject valve closed.
Never allow the unit to freeze or operate with a feed water temperature above 100F.
NOTES
Changes in operating variables are beyond the control of the system manufacture. The end user
is responsible for the safe operation of this equipment. The suitability of the product water for
any specific application is the responsibility of the end user.
Successful long-term performance of an RO system depends on proper operation and
maintenance of the system. This includes the initial system startup and operational startups and
shutdowns. Prevention of fouling or scaling of the membranes is not only a matter of system
design, but also a matter of proper operation. Record keeping and data normalization are
required in order to know the actual system performance and to enable corrective measures when
necessary. Complete and accurate records are also required in case of a system performance
warranty claim.
Changes in the operating parameters of an RO system can be caused by changes in the feed
water or can be a sign of trouble. Maintaining an operation and maintenance log is crucial in
diagnosing and preventing system problems. For your reference, a typical log sheet is included
in this manual.

TABLE OF CONTENTS
I. Introduction
A. Specifications
B. RO Overview
C. Pre-treatment
II. Controls, Indicators, and Components
III. Operation
A. Installation
B. Plumbing Connections
C. Electrical
D. Startup
E. Control Function
F. Operation and Maintenance Log
G. Troubleshooting
IV. Replacement Parts List
V. Membrane Replacement
VI. Appendix
Temperature Correction Factors

I. INTRODUCTION
The separation of dissolved solids and water using RO membranes is a pressure driven
temperature dependent process. The membrane material is designed to be as permeable to water
as possible, while maintaining the ability to reject dissolved solids.
The main system design parameters require the following:
Internal flows across the membrane surface must be high enough to prevent settling of fine
suspended solids on the membrane surface.
The concentration of each dissolved ionic species must not exceed the limits of solubility
anywhere in the system.
Pre-treatment must be sufficient to eliminate chemicals that would attack the membrane
materials.
A. SPECIFICATIONS
Notes:
Maximum production based on a feed water of 77°F, SDI < 1, 1000 ppm TDS, and pH 7.
Individual membrane productivity may vary (± 15%). May be operated on other feed waters with reduced
capacity.
Percent Rejection is based on membrane manufactures specifications; overall system percent rejection may
be less.
R4X40-1
R4X40-2
R4X40-3
Maximum Productivity (gallons per day)
2200
4400
6600
Quality (average membrane rejection)
98 %
Recovery (user adjustable)
15 - 75 %
25 –75%
32 - 75 %
Membrane Size
4” x 40”
Number Of Membranes
1
2
3
Prefilter (system ships with one 5 micron cartridge)
20”
Feed Water Connection
3/4" NPTF
Product Water Connection (tubing OD)
5/8"
Reject Water Connection (tubing OD)
5/8"
Feed Water Required (maximum)
10 gpm
12 gpm
14 gpm
Feed Water Pressure (minimum)
10 psi
Drain Required (maximum)
10 gpm
12 gpm
14 gpm
Electrical Requirement (60 Hz)
120 V - 15 amps
120 V - 20 amps
240 V - 12 amps
Motor Horse Power
3/4
1
1 1/2
Dimensions W x D x H (approximate inches)
20 x 20 x 50
20 x 26 x 50
Shipping Weight (estimated pounds)
120
150
180

B. RO OVERVIEW
Reverse osmosis systems utilize semipermeable membrane elements to separate the feed
water into two streams. The pressurized feed water is separated into purified (product) water
and concentrate (reject) water. The impurities contained in the feed water are carried to drain
by the reject water. It is critical to maintain adequate reject flow in order to prevent
membrane scaling and/or fouling.
RO Membrane
Feed Water Product Water
Reject Water
C. PRETREATMENT
The RO feed water must be pretreated in order to prevent membrane damage and/or fouling.
Proper pretreatment is essential for reliable operation of any RO system.
Pretreatment requirements vary depending on the nature of the feed water. Pretreatment
equipment is sold separately. The most common forms of pretreatment are described below.
Media Filter - Used to remove large suspended solids (sediment) from the feed water.
Backwashing the media removes the trapped particles. Backwash can be initiated by time or
differential pressure.
Water Softener - Used to remove calcium and magnesium from the feed water in order to prevent
hardness scaling. The potential for hardness scaling is predicted by the Langelier Saturation
Index (LSI). The LSI should be zero or negative throughout the unit unless approved anti-
scalents are used. Softening is the preferred method of controlling hardness scale.
Carbon Filter - Used to remove chlorine and organics from the feed water. Free chlorine will
cause rapid irreversible damage to the membranes.
The residual free chlorine present in most municipal water supplies will damage the thin film
composite structure of the membranes used in this unit. Carbon filtration or sodium bisulfite
injection should be used to completely remove the free chlorine residual.
Chemical Injection - Typically used to feed antiscalant, coagulant, or bisulfite into the feed water
or to adjust the feed water pH.

Prefilter Cartridge - Used to remove smaller suspended solids and trap any particles that may be
generated by the other pretreatment. The cartridge(s) should be replaced when the pressure drop
across the housing increases 5 - 10 psig over the clean cartridge pressure drop.
The effect of suspended solids is measured by the silt density index (SDI) test. An SDI of five
(5) or less is specified by most membrane manufacturers and three (3) or less is recommended.
Iron & Manganese - These foulants should be removed to less than 0.1 ppm. Special media
filters and/or chemical treatment is commonly used.
pH - The pH is often lowered to reduce the scaling potential. If the feed water has zero hardness,
the pH can be raised to eliminate CO2.
Silica: Reported on the analysis as SiO2. Silica forms a coating on membrane surfaces when the
concentration exceeds its solubility. Additionally, the solubility is highly pH and temperature
dependent. Silica fouling can be prevented with chemical injection and/or reduction in recovery.
II. CONTROLS, INDICATORS, and COMPONENTS (see figure 1)
A. On / Off Switch –Turns the unit on and off.
B. Power, low-pressure, tank level, and pretreatment indicators.
C. Reject Control Valve - Controls the amount of reject flow.
D. Reject Recycle Control Valve –Controls the amount of recycle flow.
E. Prefilter Outlet Pressure Gauge - Indicate the outlet pressures of the prefilter.
F. Pump Discharge Pressure Gauge - Indicates the membrane feed pressure.
G. Reject Flow Meter - Indicates the reject flow rate in gallons per hour (gph).
H. Product Flow Meter - Indicates the product flow rate in gallons per hour (gph).
I. Prefilter Housing - Contains the RO prefilter.
J. RO Feed Pump - Pressurizes the RO feed water.
K. RO Membrane Housing(s) - Contains the RO membrane(s).
L. Water Quality Meter –Indicates the quality of the feed and product water in parts per
million of total dissolved solids (PPM –TDS).
M. Feed Water Inlet.

Figure 1

Figure 2
Controller Connections

III. OPERATION
A. INSTALLATION
1. Proper pretreatment must be determined and installed prior to the RO system.
2. The water supply and pretreatment equipment should be sufficient to provide a
minimum of 10-psig at the maximum feed flow.
3. An electrical receptacle with a ground fault interrupt (GFI) is highly recommended.
4. Responsibility for meeting local electrical and plumbing codes lies with the owner /
operator.
5. Install indoors in an area protected from freezing. Space allowances for the removal
of the membranes from the pressure vessels should be provided.
6. Verify that a prefilter cartridge is installed in the housing. (see figure #1, item I).
B. PLUMBING CONNECTIONS
Note: It is the responsibility of the end user to ensure that the installation is done according to
local codes and regulations.
1. Connect the pretreated feed water line to the prefilter inlet (Figure # 1 item M). A
feed water shutoff valve should be located within 10 feet of the system.
2. Temporarily connect the product water outlet to a drain. The product outlet is located
behind the panel at the top of the product flow meter. The product water line should
never be restricted. Membrane and/or system damage may occur if the product line is
blocked.
3. Connect the reject water outlet to a drain. The reject outlet is located behind the
panel at the top of the reject flow meter. The reject drain line should never be
restricted. Membrane and/or system damage may occur if the reject drain line is
blocked. An air gap must be located between the end of the drain line and the drain.
The use of a standpipe or other open drain satisfies most state and local codes and
allows for visual inspection and sampling.
C. ELECTRICAL
Note: It is the responsibility of the end user to ensure that the installation is done according to
local codes and regulations.
1. Make sure the on / off switch in the off position (Figure # 1 item A).
2. Plug the unit into a 115 volt 3 prong outlet. Note –The R4X40-2 requires a 20 amp
outlet. Systems configured for 230 volts do not come with a plug.
3. If a tank level switch and/or pretreatment interlock is used, remove the jumper(s)
from the terminals on the controller and install the switch leads into the terminals (see
figure #2). The tank level and pretreatment interlock switches should be closed for the
RO system to run. When the circuit is open the RO system turns off and the front
panel indicator turns on.