For Residential and Commercial Applications
ES-LF25AUB
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LF25AUB-Z3
EPDM
diaphragm
Integral
stainless
steel strainer
Union inlet
connection
Replaceable
seat module
Bypass valve
assembly for 1
1
4" – 2"
(32 – 50mm) sizes
Bypass for
1
2" – 1"
(15 – 25mm)
sizes
Series LF25AUB-Z3
Water Pressure Reducing Valves**
Sizes:
1
2" – 2"
Series LF25AUB-Z3 Water Pressure Reducing Valves are designed to
reduce incoming water pressure to a sensible level to protect plumbing
system components and reduce water consumption. This series is suitable
for water supply pressures up to 300psi (20.7 bar) and may be adjusted
from 25 – 75psi (172 – 517 kPa). The LF25AUB-Z3 features Lead Free*
construction to comply with Lead Free* installation requirements. The
standard setting is 50psi (345 kPa). All parts are quickly and easily service-
able without removing the valve from the line. The standard bypass feature
permits the flow of water back through the valve into the main when pres-
sures, due to thermal expansion on the outlet side of the valve, exceed the
pressure in the main supply.
Features
Standard construction includes Z3 sealed spring cage and stainless steel
corrosion resistant adjusting & cage screws
• Union inlet connection
• Integral stainless steel strainer
• Replaceable seat module
• Lead Free* cast copper silicon alloy construction
• Serviceable in line
• Bypass feature controls thermal expansion pressure***
• High temperature resistant reinforced diaphragm for hot water
Specifications
A Water Pressure Reducing Valve with integral strainer shall be installed in the
water service pipe near its entrance to the building where supply main pressure
exceeds 60psi (413 kPa) to reduce it to 50psi (345 kPa) or lower. The water
pressure reducing valve shall be constructed using Lead Free* materials. Lead
Free* regulators shall comply with state codes and standards, where applicable,
requiring reduced lead content. The valve shall feature a Lead Free* cast copper
silicon alloy suitable for water supply pressures up to 300psi (20.7 bar). Provision
shall be made to permit the bypass flow of water back through the valve into the
main when pressures, due to thermal expansion on the outlet side of the valve,
exceed the pressure in the main supply. Water Pressure Reducing Valve with
built-in bypass check valves will be acceptable. Approved valve shall be listed to
ASSE 1003 and IAPMO and certified to CSA B356. Valve shall be a Watts Series
LF25AUB-Z3.
LEAD FREE
*
* The wetted surface of this product contacted by consumable water contains less
than 0.25% of lead by weight.
** A water saving test program concluded that reducing the supply pressure from
80-50psi (551-345 kPa) resulted in a water savings
of 30%.
*** The bypass feature will not prevent the pressure relief valve from opening on the hot
water supply system with pressure above 150psi (10.3 bar).
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 with-
out prior notice and without incurring any obligation to make such changes and modifications on Watts products previously or subsequently sold.
Materials
Body: Lead Free* copper silicon alloy
Seat:
1
2"–1" (15–25mm) Replaceable engineered polymer
(10% glass filled Noryl
®
)
1
1
4"–2" (32–50mm) Replaceable stainless steel
Integral Strainer: Stainless steel
Diaphragm: Reinforced EPDM with PTFE wetted surface
Valve Disc: EPDM
Product is for interior or exterior applications. Product should not be buried
directly in the ground. For exterior applications where the valve will be situated
in a vault or pit or be in contact with the ground, the valve should be installed
in a meter box/vault, accessible for repair and adjustment, per local code.
The information contained herein is not intended to replace the full product
installation and safety information available or the experience of a trained
product installer. You are required to thoroughly read all installation instruc-
tions and product safety information before beginning the installation of this
product.
NOTICE
G
Pressure – Temperature
Temperature Range: 33°F – 160°F (0.5°C – 71°C)
Maximum Working Pressure: 300psi (20.7 bar)
Adjustable Reduced Pressure Range: 25–75psi (172 – 517 kPa)
Standard Reduced Pressure Setting: 50psi (345 kPa)
Options
Add Suffix
-“ ” Threaded female union inlet x NPT female outlet
-S Solder union inlet x NPT female outlet
-QC Quick-Connect union inlet (
1
2",
3
4", 1")
-LF Double union body less fittings (
3
4", 1", 1
1
4")
-w/press**** Press inlet x press outlet (non union)
-DU Double Union – NPT threaded union female inlet and outlet
-S-DU Double Union –Solder union inlet and outlet
-DU-PEX Double Union –PEX union inlet and outlet
-DU-QC Double Union – Quick-Connect inlet and outlet (
1
2",
3
4", 1")
-G Gauge tapping,
1
4"
-GG Gauge tapping and 160psi (11 bar) gauge
-HP High pressure range 75–125psi (5.2 – 8.6 bar) †
-LP Low pressure range 10–35psi (69 – 241 kPa) †
-Z7 400psi (27.6 bar) initial pressure,
1
2" models only
-Z6 Water meter threaded connections and 7
1
2" (190mm) lay
length for new or existing meter box installations, For
5
8",
5
8"
x
3
4" or
3
4" meter setters or resetters
Not available on G or GG models
Noryl
®
is a registered trademark of SABIC Innovative Plastics™
**** Viega ProPress
®
connections are optional factory installed fittings on
each end of the approved/certified assembly.
SIZE DIMENSIONS WEIGHT
D
F
G ET ES EP FQC
in. in. mm in. mm in. mm in. mm in. mm in. mm in. mm lbs. kgs.
1
2 1
1
2 38 9
7
16 240 3
1
8 79
1
2 13
1
2 13 1
1
2 38 3.5 1.6
3
4 1
1
2 38 9
7
16 240 3
1
8 79
1
2 13
3
4 19
5
8 16 1
11
16 42 3.5 1.6
1 1
3
4 44 1 0
7
16 266 3
5
8 92
5
8 16
15
16 23
13
16 21 1
3
4 45 6.5 3.0
1
1
4 2
1
8 54 11
7
16 291 3
5
8 92
5
8 16 1 25 10 4.5
1
1
2 2
3
8 60 11
15
16 304 4
1
16 103
5
8 16 1
1
16 28 10 4.5
2 3
1
4 83 13
11
16 348 4
3
4 121
5
8 16 1
5
16 34 15 6.8
Dimension includes optional gauge
Consult factory for dimensions with press connections.
SIZE DIMENSIONS
A A1 A2 B B1 B2 C
in. in. mm in. mm in. mm in. mm in. mm in. mm in. mm
1
2 5
3
8 137 5
5
16 135 5
3
16 132 6
7
16 164 6
3
8 162 7 178
3
4 5
5
16 135 5
1
2 140 5
1
4 133 6
1
2 165 6
7
8 175 6
3
4 171 7 178
1 6 152 6
1
4 159 5
7
8 149 7
3
8 187 7
13
16 198 7
11
16 195 8 203
1
1
4 8
3
4 222 8
15
16 227 8
1
4 210 10
3
4 273 11 279 9 229
1
1
2 8
3
4 222 9 229 8
1
4 210 10
3
4 273 11
3
16 284 9
1
2 241
2 9
1
4 235 10 254 8
3
4 222 11
5
16 287 12
11
16 322 11
1
4 286
Standards
Meets requirements of ASSE Standard 1003: ANSI A112.26.2: CSA Stan-
dard B356; Southern Standard Plumbing Code and listed by IAPMO.
Military Standard MIL-V-18146B Type I.
Capacity
C (Max)
F* (Max)
D
B, B1, B2
A, A1
EP
ES
ET
A2
A - LF25AUB-Z3
A1 - LF25AUB-S-Z3
A2 - LF25AUB-DU-LF-Z3
B - LF25AUB-DU-Z3
B1 - LF25AUB-S-DU-Z3
B2 - LF25AUB-DU-THDxPEX-Z3
ET - NPT Engagement for tight joint
ES - Female sweat socket depth
EP - PEX end connection
FQC - Quick-Connect union
FQC
Sizes:
1
2",
3
4", 1", 1
1
4", 1
1
2", 2"
kPa psi
0 0
34 5
69 10
103 15
138 20
172 25
0 10 20 30 40 50 60 70 80 90 100 gpm
0 38 76 114 152 190 228 266 304 342 380 lpm
Reduced Pressure Drop
Flow
1
2
3
4
1”
2”
1
1
4
1
1
2
Dimensions — Weights
ES-LF25AUB 1734 © 2017 Watts
USA: T: (978) 689-6066 • F: (978) 975-8350 • Watts.com
Canada: T: (905) 332-4090 • F: (905) 332-7068 • Watts.ca
Latin America: T: (52) 81-1001-8600 • Watts.com