3
Parallel
Indoors
Above Ground
12" min.
Refer to
Local Codes
12" min.
Refer to
Local Codes
Strainer
12" min.
Refer to Local Codes
Insulated Enclosure
Installation
A. Install the assembly in a horizontal po si tion. The shutoff valve with
the test cock is to be mounted on the inlet side of the back flow
pre ven ter. The test cock is on the in let side of the shut off valve.
B. Always install the assembly in an ac ces si ble lo ca tion to fa cil i tate
test ing and ser vic ing. Check the state and local codes to en sure
that the back flow pre ven ter is installed in com pli ance, such as the
prop er height above the ground. The back flow preventer must
be sup port ed and is not de signed to car ry full weight of the
stand pipe.
C. Vent water discharge from the relief valve in ac cor dance with
code re quire ments. The relief valve should never be sol id ly piped
into a drain age ditch, sew er, or sump. The dis charge should be
funneled through a Watts air gap fitting piped to a floor drain.
D. Install a strainer ahead of the assembly to pro tect the discs from
un nec es sary foul ing.
Start Up
A. After closing the downstream shutoff, open the upstream shutoff
slowly, fill the valve, and bleed the air through test cocks No. 2,
No. 3, and No. 4. When the valve is filled, open the down stream
shutoff slowly and fill the wa ter sup ply sys tem.
B. Install an air gap with the drain line terminating above a floor drain
to handle any normal dis charge or nuisance spit ting through the
relief valve. The floor drain size may need to be de signed to pre-
vent water damage caused by a fail ure con di tion. Do not reduce
the size of the drain line from the air gap fit ting.
C. Consider piping two or more smaller valves in parallel, when
approved, to serve a large supply pipe main. This type of in stal la-
tion is employed where in crease capacity is needed be yond that
pro vid ed by a single valve and per mits test ing or ser vic ing of an
in di vid u al valve with out shut ting down the com plete line.
The number of assemblies used in par al lel should be de ter mined
by the en gi neer’s judgment based on the op er at ing conditions of a
spe cif ic in stal la tion.
