Watts LF919 - Manual

Series LF919
Reduced Pressure Zone
Assemblies
Sizes: 1 ⁄
2
" – 2" (15 – 50mm)
Series LF919 Reduced Pressure Zone Backflow Assemblies are
designed to protect potable water supplies in accordance with
national plumbing codes and water authority requirements. This
series can be used in a variety of installations, including the preven-
tion of health hazard cross-connections or for containment at the
service line entrance.
This series features two poppet style check valves, replaceable
check seats, with an intermediate relief valve. Its compact modular
design facilitates easy maintenance and assembly access. Sizes
1 ⁄
2
" – 1" (15 – 25mm) shutoffs have tee handles. The LF919 fea-
tures Lead Free* construction to comply with Lead Free* installation
requirements.
Features
• Separate access covers for the check valves and relief valve
for ease of maintenance
• Top entry-all check internals easily accessible
• All rubber elastomers of chloramine resistant material
• Check valve poppet assemblies are fully guided by innovative
plastic seat guide
• Replaceable push-in check valve and relief valve seats
eliminates threads from the water way
• EZ twist relief valve cover quarter-turn locking joint captures
the spring load during repair to facilitate disassembly
• Innovative check valve plastic cover bushing provides trouble
free guiding of the check valve poppet
• Bottom mounted relief valve provides reduced installation
clearances
• Compact, space saving design
• No special tools required for servicing
• Top mounted test cocks for ease in testing and reduced
installation clearances
• Standardly furnished with NPT body connections
Specifications
A Reduced Pressure Zone Assembly shall be installed at each
potential health hazard location to prevent backflow due to back-
siphonage and/or backpressure. The assembly shall consist of a
pressure differential relief valve located in a zone between two posi-
tive seating check valves. Seats and seat discs shall be replace-
able in both check valves and the relief valve without the use of
special tools. Service of all internal check valve components shall
be through top mounted access covers threaded to the main valve
body. The check valve poppet assembly shall be guided via the
use of a corrosion resistant plastic guide. The check valve and
relief valve seats shall be push-in type. The relief valve cover shall
be secured with stainless steel bolts and shall utilize a quarter-turn
locking joint to capture the spring load of the relief valve. The relief
valve shall have an internal sensing line to sense the inlet water sup-
ply. All rubber elastomers shall be of chloramine resistant material.
The assembly shall also include two resilient seated isolation valves,
four top-mounted resilient seated test cocks and an air gap drain
fitting. The Lead Free* Reduced Pressure Zone Assembly shall
comply with state codes and standards, where applicable, requiring
reduced lead content. The assembly shall be a Watts Series LF919.
For Health Hazard Applications
ES-LF919
LF919QT 3 ⁄
4
" (20mm)
Now Available
WattsBox Insulated Enclosures.
For more information, refer to literature ES-WB.
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.
LEAD FREE
*
Job Name ––––––––––––––––––––––––––––––––––––––––––– Contractor ––––––––––––––––––––––––––––––––––––––––––––
Job Location ––––––––––––––––––––––––––––––––––––––––– Approval –––––––––––––––––––––––––––––––––––––––––––––
Engineer ––––––––––––––––––––––––––––––––––––––––––––– Contractor’s P.O. No. ––––––––––––––––––––––––––––––––––
Approval ––––––––––––––––––––––––––––––––––––––––––––– Representative ––––––––––––––––––––––––––––––––––––––––
*The wetted surface of this product contacted by consumable
water contains less than 0.25% of lead by weight.
NOTICE
Inquire with governing authorities for local installation requirements