For Residential and Commercial Applications
Contractor’s P.O. No.
assembly for 1
⁄4" – 2"
(32 – 50mm) sizes
⁄2" – 1"
(15 – 25mm)
Water Pressure Reducing Valves**
⁄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.
• 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
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
* 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
*** 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.
Body: Lead Free* copper silicon alloy
⁄2"–1" (15–25mm) Replaceable engineered polymer
(10% glass filled Noryl
⁄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