Installation, Maintenance, and Repair Manual
Series 757, 757DCDA, LF757DCDA
Double Check Valve Assemblies
Double Check Detector Assemblies
2
⁄
" – 10"
1
2
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.
WARNING
!
You are required to consult the local building and plumbing
codes prior to installation. If the information in this manual
is not consistent with local building or plumbing codes,
the local codes should be followed. Inquire with governing
authorities for additional local requirements.
WARNING
!
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.
If installed on a fire suppression system, all mechanical
checks, such as alarms and backflow preventers, should be
flow tested and inspected in accordance with NFPA 13 and/
or NFPA 25. All products must be retested once maintenance
has been performed. 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.
WARNING
!
Do not impede or prevent sleeve movement by installing
riser cradle clamps or other obstructive elements on
or around the sleeve. Sleeve movement is required to
service the backflow.
NOTICE
For Australia and New Zealand, line strainers should be installed
between the upstream shutoff valve and the inlet of the backflow
preventer.
Testing
For field testing procedure, refer to IS-TK-DL, IS-TK-9A, IS-TK-99E,
and IS-TK-99D at watts.com.
For technical assistance, contact your local Watts
Installation Guidelines
Most field problems occur because dirt and debris present in
the system at the time of installation become trapped in check
No. 1. Flush the system before the backflow valve is installed.
If the system is not flushed until after the backflow valve is
installed, remove both check modules from the valve and open
the inlet shutoff to allow water to flow for a sufficient time to
flush debris from the water line. If debris in the water system
continues to cause fouling, a strainer can be installed upstream
of the backflow assembly.
Series 757 and 757DCDA/LF757DCDA can be installed in either
horizontal or vertical position as long as the backflow assembly
is installed in accordance with the direction of the flow arrow on the
assembly and the local water authority approves the installation.
(See illustrations of horizontal and vertical installations on p. 2.) The
assembly should be installed with adequate clearance around
the valve to allow for inspection, testing and servicing. Ensure
a minimum clearance of 12" between the lower portion of the
assembly and the floor or grade.
NOTICE
Assembly body should not be painted.
representative.
®
RP/IS-757/757DCDA
757 OSY