2
Watts Series 709 Double Check Valve
may be installed in either a vertical or hori-
zontal position.
Install valve in the line with arrow on valve
body pointing in the direction of fl ow.
They should always be installed in an
accessible location to facilitate testing
and servicing.
Pipe lines should be thoroughly fl ushed to
remove foreign material before installing
the unit. A strainer should be installed as
shown, ahead of backfl ow preventers to
prevent discs from unnecessary fouling.
CAUTION:
Do not install with strainer
when backfl ow preventer is used on sel-
dom-used water lines which are called
upon during emergencies, such as fi re
sprinkler lines, etc.
It is important that Series 709 be tested
periodically in compliance with local
codes, but at least once a year or more
often, depending upon system conditions.
(Send for IS-TK-7).
Indoor Installations
For indoor installations, it is important that
the valve be easily accessible to facilitate
testing and servicing.
Outdoor Installations
In area where freezing conditions do not
occur, Series 709 can be installed outside of
a building. The most satisfactory installation
is above ground and should be installed in
this manner whenever possible.
It is generally recommended that backfl ow
preventers never be placed in pits unless
absolutely necessary and then only when
approved by local codes. In such cases,
a modifi ed pit installation is preferred
or an insulated above ground insulated
enclosure.
Vertical
Horizontal
Watts 709S
2
1
⁄
2
" – 10"
Strainer
Indoor Installations
▼
▼
mm A
mm
2
1
⁄
2
" – 3" 65-80
10"
300
4
100 15" 450
6
150 15" 450
8
200 23" 680
10
250 25" 750
Clearance Required
for Servicing
A
Now Available,
WattsBox Insulated
Enclosures.
For more information, send for ES-WB
or ES-WB-T.
Above Ground in Insulated Enclosure
For indoor installations, it is important that the valve be
easily accessible to facilitate testing and servicing.
Outdoor Installations
Meter
Strainer
Watts 709S
2
1
⁄
2
" – 10" (65-250mm)
Basic Installation Instructions
RP-IS-709_709DCDA.indd 2
9/26/08 2:28:14 PM
