Installation instructions, Indoors, Outside – Watts LF719 User Manual

Page 2: Parallel, Figure 1, Figure 2, Figure 3

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Indoors -

Figure 1

Check local codes for installation requirements. Pipe lines should be

thoroughly flushed to remove foreign material before installing the

unit. A strainer should be installed as shown, ahead of backflow pre-

venter to prevent disc from unnecessary fouling. Install valve in the

line with arrow on valve body pointing in the direction of flow.

For indoor installations, it is important that the valve be easily

accessible to facilitate testing and servicing. Do not install in a

concealed location.

CAUTION

Do not install with strainer when backflow preventer is used on

seldom-used water lines which are called upon during emer-

gencies, such as fire sprinkler lines, etc.

It is important that Series 719 and LF719 be tested periodically

in compliance with local codes but at least once a year or more

often depending upon system conditions. Regular inspection,

testing and cleaning assures maximum life and proper product

function.

NOTICE

Fire Protection System Installations

The National Fire Protection Agency (NFPA) Guidelines require

a confirming flow test to be conducted whenever a “main line”

valve such as the shutoff valves or a backflow assembly have

been operated. Certified testers of backflow assemblies must

conduct this test. The trim valves of the confirming flow test

must be closed during the test. When the test is completed,

the trim valves must be returned to a fully open position.

Outside -

Figure 2

Parallel -

Figure 3

Where approved by code, Watts recommends a custom engi-

neered Watts PVS Series water supply valve station consisting of

two or more 719 and LF719 Series valves piped in parallel to serve

a larger supply main. This type of installation is employed whenever

it is required to maintain water flow to a facility. Typical applications

include hospitals, multi-family dwellings, malls and other similar

applications.

A properly designed Watts PVS valve station provides redundant

flow paths, a continuous supply of adequate water, testing and

servicing of an individual valve without supply interruption, and

long service life.

The size, quantities and design of parallel valve installations should

be exactly in accordance with the engineer’s judgment and the pub-

lished Best Practice Guide of Watts wherever possible. For a copy

of the Watts Best Practice Guide, call Watts at 1-800-617-3274.

Installation Instructions

Series 719 and LF719 Double Check Valve Assemblies

719AQT

Meter Box Installation

First Shutoff

Valve

719QT-S/LF719QT-S Vertical flow-up installation

Strainer

Min. 12"

Fiberglass WattsBox

Now Available, WattsBox Insulated Enclosures.

For more information, send for ES-WB or ES-WB-T.

Figure 2

719QT-S/LF719QT-S

First

Shutoff Valve