Watts LF919 User Manual

Series lf919, Lead free, Reduced pressure zone assemblies

Series LF919

Reduced Pressure Zone

Assemblies

Sizes:

⁄

" – 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" (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

⁄

" (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