Watts 994 User Manual
Installation, Maintenance, & Repair
Series 994/994RPDA
Reduced Pressure Zone Assemblies
Reduced Pressure Detector Assemblies
Sizes: 21⁄2" – 10" (65 – 250mm)
!
WARNING
Read this Manual BEFORE using this equipment.
Failure to read and follow all safety and use information
can result in death, serious personal injury, property
damage, or damage to the equipment.
Keep this Manual for future reference.
RP/IS-994/994RPDA
Local building or plumbing codes may require modifications to the
information provided. You are required to consult the local building and
plumbing codes prior to installation. If this information is not consistent
with local building or plumbing codes, the local codes should be followed.
Need for Periodic Inspection/Maintenance: This product must be
tested periodically in compliance with local codes, but at least once per
year or more as service conditions warrant. Corrosive water conditions,
and/or unauthorized adjustments or repair could render the product
ineffective for the service intended. Regular checking and cleaning of the
product’s internal components helps assure maximum life and proper
product function.
NOTICE
Inquire with governing authorities for local installation requirements
NOTICE
For Australia and New Zealand: Pipeline strainers should be installed
between the upstream shutoff valve and the inlet of the backflow
preventer.
Testing
For field testing procedure, refer to Watts installation sheets
IS-TK-DP/DL, IS-TK-9A, IS-TK-99E and IS-TK-99D found on
www.watts.com.
For troubleshooting guide, refer to literature S-TSG.
For other repair kits and service parts, refer to our Backflow Prevention Products Repair Kits & Service Parts price list PL-RP-BPD
found on www.watts.com.
For technical assistance, contact your local Watts representative.
994
Basic Installation Instructions
Series 994 Reduced Pressure Zone Assemblies
NOTICE
The flange gasket bolts for the gate valves should be re tight ened during
in stal la tion as the bolts may have loos ened due to storage and ship ping.
#3 Test Cock
#2 Test Cock
Inlet Shutoff
Valve
#1 Test Cock
1st Check
Sensing
Line
Location and Installation Considerations
1. Backflow preventers must be installed in high-visibility lo ca tions in
order to allow for immediate notice of telltale discharge or oth er
mal func tion. This location should also facilitate testing and ser vicing and protect against freezing and vandalism.
2. Installation procedures must comply with all state and lo cal
codes.
3. Installing a backflow preventer in a pit or vault is not rec om mended. An air gap be low the relief port must be maintained so as to
avoid flood ing and sub mer sion of the assembly, which may lead
to a cross-connection. Watts recommends installations in doors
or above ground in an in su lat ed enclosure. (Refer to literature
ES-WB)
4. A strainer should be installed ahead of the backflow pre ven ter to
protect the discs from unnecessary fouling.
!
CAUTION
Do not install a strainer ahead of the backflow pre ven ter on
seldom-used, emergency water lines (i.e. fire sprinkler lines). The
strainer mesh could potentially become clogged with debris present in the water and cause water blockage during an emer gen cy.
5. Normal discharge and nuisance spitting are ac com mo dat ed by
the use of a Watts air gap fitting and a fabricated indirect waste
line. Floor drains of the same size MUST be provided in case of
ex ces sive discharge.
6. When a Series 994 backflow preventer is installed for dead-end
ser vice applications, dis charge from the relief vent may occur
due to wa ter supply pressure fluc tu a tion during static no-flow
con di tions. A check valve may be re quired ahead of the backflow
preventer.
#4 Test Cock
Outlet
Shutoff
Relief
Valve
7. ASSEMBLY: If the backflow preventer is disassembled dur ing
in stal la tion, it MUST be reassembled in its proper order. The gate
valve with the test cock is to mounted on the inlet side of the
back flow pre ven ter. The test cock must be on the inlet side of the
wedge. Failure to reassemble correctly will result in possible wa ter
damage due to excessive discharge from the relief port/vent and
possible mal func tion of the backflow preventer.
8. Prior to installation, thoroughly flush pipe line to re move any foreign matter.
9. START UP at Initial Installations and After Servicing: The down-
stream shutoff should be closed. Slowly open upstream shutoff
and allow the backflow preventer to fill slowly. Bleed air at each
test cock. When backflow preventer is filled, slowly open the
down stream shut off and fill the water supply system. This is neces sary to avoid water hammer or shock damage.
#2 Check
NOTICE
Assembly body should not be painted.
Figure 1
VALVE SIZE
in. mm
21⁄2 65 55 gpm 2
3 80 112 gpm 3
4 100 170 gpm 4
6, 8, 10 150, 200, 250 350 gpm 5
TYPICAL FLOW RATES AS
SIZED BY FLOOR DRAIN
MANUFACTURERS
DRAIN SIZE
2
Series 994 Installation Instructions
Installation
A. Series 994 shall be installed 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 shutoff valve.
B. The 994 should always be installed 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. Water discharge from the relief valve should be vented 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. Watts recommends a strainer be in stalled ahead of Watts Series
994 as sem blies to pro tect the discs from un nec es sary foul ing.
!
CAUTION
Do not install a strainer ahead of the backflow pre ven ter on
seldom-used, emergency water lines (i.e. fire sprinkler lines). The
strainer mesh could potentially become clogged with debris present in the water and cause water blockage during an emer gen cy.
Start Up
E. The downstream shutoff should be closed. Open up stream slow-
ly, fill the valve and bleed the air through Test cock 2, 3 and 4.
When valve is filled, open the down stream shutoff slowly and fill
the wa ter sup ply sys tem. This is nec es sary to avoid wa ter hammer or shock dam age.
F. The installation of a Watts air gap with the drain line ter mi nat ing
above a floor drain will handle any normal dis charge or nuisance
spit ting through the relief valve. How ev er, floor drain size may
need to be de signed to pre vent water damage caused by a cat astroph ic fail ure con di tion. Do not reduce the size of the drain line
from the air gap fit ting.
G. Two or more smaller size valves can be piped in parallel (when
ap proved) to serve a large supply pipe main. This type of in stal lation 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 judge ment based on the op er at ing conditions
of a spe cif ic in stal la tion.
Above Ground
12” (300mm) min.
Refer to
Local Codes
994
12” (300mm) min.
Refer to
Local Codes
*Insulated Enclosure
Indoors
Strainer
Parallel
994
12” (300mm) min.
Refer to Local Codes
994
*For additional information on Watts insulated enclosures refer to literature ES-WB.
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