
For Commercial Applications
ES-WQ-PWS20_S20-2
Job Name
Job Location
Engineer
Approval
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Series PWS20 and
Series PWS20-2
Commercial Water Softening
Systems
Connection Size: 2" (50mm)
Flow Rates: Up to 105 gpm (397 lpm)
Watts Pure Water Series PWS20 and PWS20-2 water softening
systems are highly efficient conventional cation exchange type
water softeners. They are suitable for commercial applications
ranging from 90,000 to 600,000 grains of hardness removal
per tank and flow rates up to 105 gallons per minute (397 lpm).
Where continuous softened water is required PWS20-2 duplex
alternating systems can be specified for uninterrupted service.
Regeneration is meter demand initiated. All cycles of regeneration are fully automatic and do not require manual actuation.
Watts Pure Water Series PWS20 and PWS20-2 water softeners are designed for point of use or point of entry applications
where the benefits of softened water are required. These systems exchange scale-forming calcium and magnesium ions
with non scale-forming sodium ions to create soft water for a
variety of applications.
Steam boiler make up water, water heater pretreatment,
reverse osmosis pretreatment, cooling tower make up water,
sterilizer make up water, washing, and process water are all
common applications for the Watts Pure Water Series PWS20
and PWS20-2 water softeners.
Softened water provides a wide variety of benefits from not
introducing scale into pipes, valves, water heating equipment,
heat exchangers, and cooling towers to reducing mineral build
up in areas that see excessive splashing such as food preparation counters and sink areas. Softened water also conserves
soaps and cleaning agents by eliminating the formation of soap
curd, so your cleaners can work on cleaning – not reacting with
the hardness in your water.
Features
• WQA Certified fully automatic metered demand control valve
• Sophisticated digital electronic controls that store operating
history that can be accessed by the user
• Fully adjustable regeneration cycles
• Durable brass bodied control valve for years of service
• Dry contact lock out switch for remote interface is standard
• WQA Certified high capacity resin
• Highly corrosion resistant NSF Certified fiberglass tanks
• Durable polypropylene lower distribution system
Contractor
Approval
Contractor’s P.O. No.
Representative
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PURE WATER
Series PWS20-2Series PWS20
Specifications
A Watts Pure Water Series PWS20 and PWS20-2 water softening system shall be installed on the building’s main water
line just after it enters the building. The installation point shall
be after any backflow prevention or pressure regulating valves.
Other installation options are to install a system just before
the water heater or other types of equipment needing the
protection of softened water. In installations where dedicated
cold water make up to a water heater is the installation point,
a backflow preventer and a thermal expansion tank must be
installed as well. The system shall be installed with a bypass
valve to allow for the shut down and removal of the unit without interrupting the water supply to the building.
The water softener shall be a down flow regenerated, metered
demand, sodium cycle cation exchange type system with all
components necessary for proper operation. Electrical requirements are 120 volt 60 hertz. A local drain is required to accept
drain water from the system. The feed water pressure must not
fall below 25psi or exceed 125psi. Water temperature must not
fall below 34°F or exceed 110°F (1°C - 43°C).
The system shall provide softened water measuring less than
one grain per gallon of hardness as Calcium Carbonate when
operated within the manufacturer’s operational specifications.
Standards
Control Valve- WQA Certified to NSF/ANSI Std. 61
Ion Exchange Resin- WQA Certified to NSF/ANSI Std. 44
Mineral Tank- NSF Certified to ANSI Std. 44 or 61
Watts product specifications in U.S. customary units and metric are approximate and are provided for reference only. For precise measurements,
please contact Watts Technical Service. Watts reserves the right to change or modify product design, construction, specifications, or materials without prior notice and without incurring any obligation to make such changes and modifications on Watts products previously or subsequently sold.

Feed Water Guidelines
pH ........................ 6 to 10
Hardness (maximum) .......... Depends on customers acceptable
hardness leakage level.
Water Pressure .............. 25psi to 125psi (171kPa to 8.5 bar)
Temperature ................. 34 - 110°F (1 - 43°C)
Free Chlorine (maximum) ....... 1mg/L
Iron (maximum) ............... 1mg/L
Oil and H2S ................. None Allowed
Turbidity ................... Less than 5.0 NTU
For all other guideline information please contact your Watts
representative.
Dimensions - Weights
Note: Do not use with water that is microbiologically unsafe or
of unknown quality without adequate disinfection before or after
the system.
PWS20
E
E
F
F
C
C
G
G
FRONT
D
D
B A
B
SIDE
C
A
E
F
FRONT
PWS20-2
D
B
G
SIDE
Series PWS20
MODEl NO. DIMENSIONS WEIGHTS
A B C D E F G
in. mm in. mm in. mm in. mm in. mm in. mm in. mm lbs. kgs.
PWS20131D11 673/8 1711 673/8 1711 777/8 1978 16 406 211/4 538 18 457 40 1016 265 120
PWS20131E11 67
PWS20131F11 68
PWS20131G11 70
PWS20131H11 76
PWS20131I11 80
PWS20131J11 86 2184 86 2184 96
3
/4 1721 673/4 1721 771/8 1959 17 432 221/4 564 18 457 40 1016 350 159
1
/2 1740 681/2 1740 7815/16 2004 181/8 460 231/4 589 24 607 41 1041 400 182
1
/2 1791 701/2 1791 8015/16 2055 211/8 536 2411/16 627 24 607 50 1270 600 273
3
/4 1949 763/4 1949 871/8 2213 241/8 613 261/4 665 30 762 50 1270 710 323
1
/4 2038 801/4 2038 905/8 2302 301/8 765 301/8 764 39 991 48 1219 1160 527
7
/16 2449 361/8 917 361/8 917 39 991 60 1524 1560 709
A
Series PWS20-2
MODEl NO. DIMENSIONS WEIGHTS
A B C D E F G
in. mm in. mm in. mm in. mm in. mm in. mm in. mm lbs. kgs.
PWS20131D21 673/8 1711 673/8 1711 777/8 1978 16 406 60 1524 18 457 40 1016 450 205
PWS20131E21 67
PWS20131F21 68
PWS20131G21 70
PWS20131H21 76
PWS20131I21 80
PWS20131J21 86 2184 86 2184 96
3
/4 1721 673/4 1721 771/8 1959 17 432 60 1524 18 457 40 1016 500 227
1
/2 1740 681/2 1740 7815/16 2004 181/8 460 70 1778 24 610 41 1041 800 364
1
/2 1791 701/2 1791 8015/16 2055 211/8 536 75 1905 24 610 50 1270 1200 545
3
/4 1949 763/4 1949 871/8 2213 241/8 613 87 2210 30 762 50 1270 1400 636
1
/4 2038 801/4 2038 905/8 2302 301/8 765 104 2642 39 991 48 1219 2200 1000
7
/16 2449 361/8 917 115 2921 39 991 60 1524 3000 1364

Specifications
MINERAl TANK BRINE TANK SOFTENING lBS. SAlT PER FlOW RATE & PRESSURE
TANK RESIN GRAVEl TANK SAlT CAPACITY REGENERATION SERV DROP BKW
MODEl NO. SIZE Ft
3
SIZE FIll MAX MIN MAX MIN GPM PSI GPM
PWS20131D11 14" x 65" 3 60 lbs. 18" x 40" 400 90 K 60 K 45 18 25/40 15/25 5
PWS20131E11 16" x 65" 4 80 lbs. 18" x 40" 400 120 K 80 K 60 24 35/55 15/25 7
PWS20131F11 18" x 65" 5 100 lbs. 24" x 41" 600 150 K 100 K 75 30 57/65 15/25 10
PWS20131G11 21" x 62" 7 100 lbs. 24" x 50" 600 210 K 140 K 105 42 60/77 15/25 12
PWS20131H11 24" x 72" 10 200 lbs. 30" x 50" 1200 300 K 200 K 150 60 74/97 15/25 15
PWS20131I11 30" x 72" 15 400 lbs. 39" x 48" 2200 450 K 300 K 225 90 80/100 15/25 25
PWS20131J11 36" x 72" 20 500 lbs. 39" x 48" 2200 600 K 400 K 300 120 84/105 15/25 35
Ordering Information
SPACE
MODEl NO. DESCRIPTION REQUIRED WEIGHT
D X W X H lBS KGS
PWS20131D11 3 Cubic Foot 2" Simplex Softener with Flow Meter 18" x 37" x 87" 265 120
PWS20131E11 4 Cubic Foot 2" Simplex Softener with Flow Meter 18" x 39" x 87" 350 159
PWS20131F11 5 Cubic Foot 2" Simplex Softener with Flow Meter 24" x 48" x 89" 400 182
PWS20131G11 7 Cubic Foot 2" Simplex Softener with Flow Meter 24" x 52" x 89" 600 273
PWS20131H11 10 Cubic Foot 2" Simplex Softener with Flow Meter 30" x 60" x 96" 710 323
PWS20131I11 15 Cubic Foot 2" Simplex Softener with Flow Meter 39" x 75" x 106" 1160 527
PWS20131J11 20 Cubic Foot 2" Simplex Softener with Flow Meter 39" x 81" x 107" 1560 709
PWS20131D21 3 Cubic Foot 2" Duplex Alternating Softener with Flow Meter 18" x 60" x 87" 450 205
PWS20131E21 4 Cubic Foot 2" Duplex Alternating Softener with Flow Meter 18" x 64" x 87" 500 227
PWS20131F21 5 Cubic Foot 2" Duplex Alternating Softener with Flow Meter 24" x 72" x 89" 800 364
PWS20131G21 7 Cubic Foot 2" Duplex Alternating Softener with Flow Meter 24" x 80" x 89" 1200 545
PWS20131H21 10 Cubic Foot 2" Duplex Alternating Softener with Flow Meter 30" x 90" x 96" 1400 636
PWS20131I21 15 Cubic Foot 2" Duplex Alternating Softener with Flow Meter 39" x 111" x 106" 2200 1000
PWS20131J21 20 Cubic Foot 2" Duplex Alternating Softener with Flow Meter 39" x 123" x 107" 3000 1364
Notes: Capacities are based on resin manufacturer’s data and are dependent upon influent water TDS, temperature, bed depth, and
flow rates. Feed water must be free of oil and color. Pipe size, tank size, and space requirements are in inches. Capacities and flow
rates expressed above are per tank. Flow rates listed at 25psi drops are for intermittent peak flow rates and are not to be used as
continuous flows.
Note: This information is not intended to replace the product
installation and safety information available or the experience of
a trained product installer. Please refer to the product installation and safety instructions for further information.

A Watts Water Technologies Company
USA: North Andover, MA • Tel. (800) 224-1299 • www.watts.com
Canada: Burlington, ON • Tel. (888) 208-8927 • www.wattscanada.ca
ES-WQ-PWS20_S20-2 1136 © 2011 Watts