Watts PWR25113021, PWR25112011, PWR25111011, PWR25113011 Installation, Operation And Maintenance Manual
Page 1
Installation, Operation
and Maintenance Manual
Wall Mounted Commercial Reverse Osmosis Systems
Series PWR2511
PURE WATER
!
WARNING
Please read carefully before proceeding with
installation. Your failure to follow any attached
instructions or operating parameters may lead to
the product’s failure, which can cause property
damage and/or personal injury.
Keep this Manual for future reference.
• Do not use where the water is microbiologically unsafe.
• Pretreatment must be sufficient to eliminate chemicals that
would attack the membrane materials.
• 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.
Save manual for future reference.
Please refer to Section 6 of this manual for operating parameters
according to your specific feed water Silt Density Index (SDI). For all
other settings according to your specific feed water quality, please
contact your Watts representative. A chemical analysis of the feed
water should be conducted prior to the initial sizing and selection of
this system.
Notes
Changes in operating variables are beyond the control of Watts. 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
B. RO Overview...................................... 2
C. Pre-treatment ..................................... 2
II. Controls, Indicators, and Components ..................3
III. Operation
A. Installation........................................ 3
B. Plumbing Connections .............................. 3
C. Electrical Connections .............................. 4
D. Startup .......................................... 4
E. Control Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
F. Operation and Maintenance Log .......................5
G. Troubleshooting ...................................6
IV. Replacement Parts List...............................7
V. Membrane Replacement .............................7
VI. Appendix ..........................................7
Temperature Correction Factors .........................7
Limited Warranty ..................................... 8
Note: Do not use with water that is microbiologically unsafe or
of unknown quality without adequate disinfection before or after
the system.
Series PWR2511
IOM-WQ-PWR2511
Page 2
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
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
Reject Water
Product Water
PWR25111011 PWR25112011 PWR25113011 PWR25113021
Maximum Productivity
(gallons per day)
Quality
(membrane rejection)
Recovery
(user adjustable)
Membrane Size 2.5" x 14" 2.5" x 21" 2.5" x 40" 2.5" x 40"
Number Of Membranes 1 1 1 2
Dimensions W x H x D
(approximate inches)
Prefilter
(system ships with one
5 micron cartridge)
Feed Water Connection
Product Water
Connection (tubing OD)
Reject Water
Connection (tubing OD)
Feed Water Required
(maximum)
Feed Water Pressure
(minimum)
Drain Required
(maximum)
Electrical Requirement 120 VAC 60 Hz 8 amps
Motor Horse Power
Shipping Weight
(estimated pounds)
150 250 600 1200
98 % 98 % 98 % 98 %
15 - 75 % 15 - 75% 15 - 75 % 30 - 75 %
22 x 32 x 12 22 x 52 x 12
10"
1
⁄2" NPT
3
⁄8"
3
⁄8"
2.4 gpm
20psi
2.4 gpm
1
⁄2
50 50 60 70
Notes:
• Maximum production based on a feed water of 77°F, SDI < 3, 1000 ppm TDS,
and pH 8.
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.
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 antiscalents 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 - Iron should be removed to less than 0.1 ppm.
Manganese should be removed to less than 0.05 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.
2
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II. Controls, Indicators, and
Components (See Figure 1)
A On / Off Switch – Turns the unit on and off.
B Product Pressure Switch – Automatically turns
the unit on and off based on the product water
pressure.
C Reject Control Valve - Controls the amount of
reject flow.
D Reject Recycle Control Valve – Controls the
amount of recycle flow.
E Prefilter Pressure Gauges - Indicate the inlet and
outlet pressures of the prefilter. The difference
between these two gauges is the prefilter
differential pressure.
F Pump Discharge Pressure Gauge - Indicates the
membrane feed pressure.
G Reject Flow Meter - Indicates the reject flow rate
in gallons per minute (gpm).
H Product Flow Meter - Indicates the product flow
rate in gallons per minute (gpm).
I Prefilter Housing - Contains the RO prefilter.
J Automatic Inlet Valve - Opens when pump is on
and closes when the pump is off.
K RO Feed Pump - Pressurizes the RO feed water.
L RO Membrane Vessel(s) - Contains the RO
membrane(s).
M Low-pressure indicator.
G
M
Figure 1
L
3
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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 suf-
ficient to provide a minimum of 20-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 al-
lowances for the removal of the membranes from the pressure
vessels should be provided.
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 inlet valve (Figure #
1 item J). 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 on 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 on 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.
!
WARNING
You will need to remove the factory installed jumper wire from
the tank level terminals in the controller.
4. If a bladder tank is used for product water storage then the
product pressure switch (Figure #1 item B) needs to be connected. Install a tee and tube fitting in the inlet piping of the
bladder tank and connect the tank to the pressure switch using
poly tubing. A check valve should be installed between the RO
unit and this tee.
5. If an atmospheric tank is used for product water storage, please
cut off the plug and wire the float switch to the tank level input
on the controller when using this float switch with a Watts
Commercial RO system.
Figure 2
Small controller used on
PWR2511, PWRO440
& PWR4011
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 is in the off position (Figure # 1
item A).
2. Plug the unit into a standard 120 volt 3 prong outlet. An outlet
protected with a ground fault interrupt (GFI) is recommended.
D. Startup
1. Verify that the pretreatment equipment is installed and working
properly. Verify that no free chlorine is present in the feed water.
2. Verify that the on / off switch is in the off position.
3. Install a 10" five micron filter cartridge in the prefilter housing.
4. Open the reject control valve completely (Figure # 1 item C) by
turning it counterclockwise.
5. Close the reject recycle control valve (Figure # 1 item D) completely by turning it clockwise.
6. Open the feed water shutoff valve installed in step III-B-1 above.
7. Move the controller on/off switch to the on position.
8. Allow the unit to run for 15 – 30 minutes to flush the preservative
from the membrane(s).
9. Adjust the reject control valves (Figure # 1 items C & D) until the
desired flows are achieved. Closing the reject valve increases
the product flow and decreases the reject flow. Opening the
reject recycle valve decreases both the reject and product flow.
See the flow rate guidelines and temperature correction table in
the appendix to determine the flow rates for different operating
temperatures. Do not exceed 200psi on the pump discharge
gauge (Figure #1 item F).
10. Allow the product water to flow to drain for 30 minutes.
11. Turn off the system and connect the product line to the point of
use. The product water line should never be restricted. Membrane and/or system damage may occur if the product line is
blocked.
12. Restart the system and record the initial operating data using the
log sheet.
E. Control Function
1. When the on / off switch is in the on position, the inlet valve
opens and the pump runs. If the product pressure switch is used
then the pump will cycle based on the product water pressure.
The switch is factory set to cut off at 40psi and cut on at 20psi.
Instructions for adjusting the cut off and cut on pressures are
located on the inside cover of the switch.
2. If the water pressure feeding the pump drops below 5psi for more
than 5 seconds, the pump will turn off and the amber light on
the control box will turn on. The controller will automatically reset
after 30 minutes and the pump will turn back on. Cycle the on /
off switch to manually reset a low-pressure shutdown.
3. Autoflush – This is a feature that provides increased reject flow
at startup and for 2 minutes every hour. The timer is preprogrammed at the factory and should not be adjusted.
Product Pressure Switch
/ Tank Level Switch
4
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REMARKS
OUTLET
PRESSURE
PRE FILTER
PRESSURE
PRE FILTER INLET
FEED WATER
CHLORINE LEVEL
HARDNESS
FEED WATER
TEMP
FEED WATER
PPM
FEED TDS PPM PRODUCT TDS
PRESSURE
DISCHARGE
DATE PRODUCT GPM REJECT GPM PUMP
F. Operation and Maintenance Log
Note: Change the prefilter when the differential pressure increases by 5 - 10psi over the clean differential pressure.
Clean the RO membrane(s) when the product flow drops by 15% or more. (See appendix)
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G. Troubleshooting
RO Membrane Troubleshooting Guide
SYMPTOMS
SALT PASSAGE PERMEATE FLOW PRESSURE DROP LOCATION POSSIBLE CAUSES VERIFICATION CORRECTIVE ACTION
Normal to increased Decreased Normal to increased Predominantly
Normal to increased Decreased Normal to increased Predominantly
Increased Decreased Increased Predominantly
Normal to moderate
increase
Decreased or moderately increased
Increased Increased Decreased Most severe in
Increased Increased Decreased Most severe in
Increased Normal to increased Decreased At random O-ring leaks, End or side
Increased Normal to low Decreased All stages Conversion too high. Check flows and pressures
Decreased Normal to moderate
increase
Decreased Normal All stages Organic fouling Destructive testing, e.g. IR
first stage
first stage
last stage
Can occur in any
stage
the first stage
the first stage
Metal oxide Analysis of metal ions in
Colloidal fouling SDI measurement of feed/
Scaling (CaSO4, CaSO3,
BaSO4, SiO2)
Biological fouling Bacteria count in permeate
Chlorine oxidant attack Chlorine analysis of feed.
Abrasion of membrane by
crystalline material
seal glue leaks.
cleaning solution.
X-ray diffraction analysis of
cleaning sol. residue.
Analysis of metal ions in
cleaning sol. Check LSI of
reject. Calculate maximum
solubility for CaSO4, BaSO4,
SiO2 in reject analysis.
and reject. Slime in pipes
and vessels.
reflection analysis.
Destructive element test.
Microscopic solids analysis
of feed. Destructive element test.
Probe test. Vacuum test.
Colloidal material passage.
against design guidelines
Improved pretreatment to remove metals. Cleaning with acid cleaners.
Optimize pretreatment system for
colloid removal. Clean with high pH,
anionic detergent formulation.
Increase acid addition and scale
inhibitor for CaSO3 and CaSO4. Reduce
recovery. Clean with an acid formulation for CaCO3, CaSO4 and BaSO4.
Shock dosage of sodium bisulfite.
Continuous feed of low conc. bisulfite
at reduced pH. Peracetic acid sterilization. Clean with alkaline anionic surfactant. Chlorine dosage upstream with
dechlorination. Replace cartridge filters.
Optimization of pretreatment system
(e.g. coagulation process.) Resin/
activated carbon treatment. Clean with
high pH detergent.
Check chlorine feed equipment and
dechlorination equipment.
Improved pretreatment. Check all filters
for media leakage.
Replace O-rings. Repair or replace
elements.
Reduce conversion rate. Calibrate
sensors. Increase analysis and data
collection.
RO System Troubleshooting
PROBLEM CORRECTIVE ACTION
High Product Water TDS
Membrane frozen, high temp, or backpressure. Replace membrane.
Membrane attack by chlorine Carbon pre-filter may be exhausted. Replace filter and membrane.
Product seal on end cap. Determine if seal or O-ring is bad. Replace as needed.
No Product Water or Not Enough Product Water
Feed water shut off. Turn on feed water.
Low feed pressure. Feed pressure must be at least 20psi. Consider booster pump.
Pre-filter cartridge clogged. Replace pre-filter cartridge.
Membrane fouled. Determine and correct cause; replace or clean membrane.
Product check valve stuck. Clean or replace check valve.
Low pump discharge pressure Adjust reject valve or replace pump
Low feed water temperature Increase membrane feed pressure or heat the feed water.
General
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IV. Replacement Parts List
A list of common replacement parts is provided below. Contact your
dealer for replacement parts assistance.
ITEM NUMBER DESCRIPTION
1 Pre filter housing 10"
2 RO membrane pressure vessel 21⁄2" x 14" SS
3 RO membrane pressure vessel 21⁄2" x 21" SS
4 RO membrane pressure vessel 21⁄2" x 40" SS
5 Pressure gauge, 2", 0-100psi, dry, bottom mount
6 Pressure gauge, 2", 0-100psi, dry, back mount
7 Pressure gauge, 21⁄2", 0-400psi, LF
8 Flow meter 0.1 – 1.0 gpm
9 Flow meter 0.2 – 2.0 gpm
10 Product pressure switch
11 Product pressure switch with auto / off lever
12 Motor 0.5 HP single phase 120 volt
13 Pump 140 GPH carbonator with relief valve
14 Low-pressure controller
15 Low-pressure switch, ¼" MPT, 3 – 40psi
16 Reject & recycle brass needle valve
17 Inlet solenoid valve, 1⁄2", 120 volt coil
18 21⁄2" x 14" RO membrane
19 21⁄2" x 21" RO membrane
20 21⁄2" x 40" RO membrane
21 Prefilter cartridge, 10", 5 micron
22 Product check valve, SS
V. Membrane Replacement
1. Turn off the system and close the feed water shutoff valve.
2. Disconnect the tubing from the pressure vessel.
3. Remove the retaining "U" pins from the pressure vessels.
4. Push the old membrane out of the vessel in the direction of the
feed flow
5. Record the serial numbers of the new membranes.
6. Lightly lubricate the brine seals on the new membranes with
clean water.
7. Install the new membranes in the direction of flow with the brine
seal end going in last.
8. Lightly lubricate the end cap internal and external O-rings with
glycerin.
9. Install the end caps and secure them with the "U" pins.
10. Reconnect the tubing to the pressure vessel.
11. Verify that all retaining "U" pins are installed.
12. Follow the start up procedure in section III-D.
VI. Appendix
The following tables are intended as a guide to determining the flow
rates for the PWR2511 series RO systems. All flows are in gallons
per minute (GPM).
Nominal flows for systems operating at 50% recovery.
MODEL NUMBER PWR25111011 PWR25112011 PWR25113011 PWR25113021
Product 0.10 0.17 0.41 0.83
Reject 0.10 0.17 0.41 0.83
Temperature Correction Factors
°C °F CORRECTION FACTOR
30 86 1.16
29 84.2 1.13
28 82.4 1.09
27 80.6 1.06
26 78.8 1.03
25 77 1.00
24 75.2 0.97
23 73.4 0.94
22 71.6 0.92
21 69.8 0.89
20 68 0.86
19 66.2 0.84
18 64.4 0.81
17 62.6 0.79
16 60.8 0.77
15 59 0.74
14 57.2 0.72
13 55.4 0.70
12 53.6 0.68
11 51.8 0.66
10 50 0.64
9 48.2 0.62
8 46.4 0.61
7 44.6 0.59
6 42.8 0.57
5 41 0.55
Multiply the nominal product flow at 25° C by the temperature correction factor to
determine the flow at various other temperatures.
Membrane
Flow Direction
Brine
Seal
7
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LIMITED WARRANTY: Certain Watts Pure Water products come with a limited warranty from Watts Regulator Co. Other products may have no warranty or are covered by the original manufacturer’s
warranty only. For specific product warranty information, please visit www.watts.com or the published literature that comes with your product. Any remedies stated in such warranties are exclusive and
are the only remedies for breach of warranty. EXCEPT FOR THE APPLICABLE PRODUCT WARRANTY, IF ANY, WATTS MAKES NO OTHER WARRANTIES, EXPRESS OR IMPLIED. TO THE FULLEST EXTENT
PERMITTED BY APPLICABLE LAW, WATTS HEREBY SPECIFICALLY DISCLAIMS ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, AND IN NO EVENT SHALL WATTS BE LIABLE, IN CONTRACT, TORT, STRICT LIABILITY OR UNDER ANY OTHER LEGAL THEORY, FOR
INCIDENTAL, INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, INCLUDING, WITHOUT LIMITATION, LOST PROFITS OR PROPERTY DAMAGE, REGARDLESS OF WHETHER IT WAS INFORMED ABOUT
THE POSSIBILITY OF SUCH DAMAGES.
IOM-WQ-PWR2511 1802 EDP# 2915862 © 2018 Watts
USA: North Andover, MA • Tel. (800) 224-1299 • www.watts.com
Canada: Burlington, ON • Tel. (888) 208-8927 • www.wattscanada.ca
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