3
Watts Series 775 Installation Instructions
Installation
A. Series 775 may be installed in a
horizontal or vertical flow up posi-
tion. The shutoff valve with the test
cock is to be mounted on the inlet
side of the backflow preventer. The
test cock is on the inlet side of the
shutoff valve.
B. The 775 should always be installed
in an accessible location to facilitate
testing and servicing. Check state
and local codes to insure that the
backflow preventer is installed in
compliance, such as the proper
height above the ground. The back-
flow preventer must be supported
and is not designed to carry full
weight of the stand pipe.
C. Backflow preventers should never
be placed in pits unless absolutely
necessary and then only when and
as approved by local codes. Con-
sult your local or state plumbing or
health inspector. Watts recom-
mends installation indoors or above
ground in an insulated enclosure.
Start Up
D. The downstream shutoff should be
closed. Open upstream slowly, fill
the valve and bleed the air through
Test cock 2, 3 and 4. When valve is
filled, open the downstream shutoff
slowly and fill the water supply sys-
tem. This is necessary to avoid wa-
ter hammer or shock damage.
E . Two or more valves can be piped in
parallel (when approved) to serve a
large supply pipe main. This type of
installation is employed where in-
crease capacity is needed beyond
that provided by a single valve and
permits testing or servicing of an in-
dividual valve without shutting down
the complete line.
The number of assemblies used in
parallel should be determined by the
engineer’s judgement based on the
operating conditions of a specific in-
stallation.
Above Ground
*Insulated Enclosure
Indoor Installation
Watts 775
Watts 775
*For additional information on Watts insulated enclosures send for ES-WB or ES-WBT.
12” min.
Refer to
Local Codes
12” min.
Refer to
Local Codes
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