Installation Instructions
1. Consult local codes for specific installation requirements and restrictions
applicable to your area. It is recommended that system supply pressure
be at least 20psi (133kPa).
2. These instructions apply to Series 850 (DC) and 856 (DCDA), sizes 2
1
⁄
2
"
to 10" only (65 – 250mm). The valves may be installed only in the orienta-
tion/flow direction as shown. The gate valves may be rotated as permit-
ted by the flange bolt pattern on vertical installations only.
3. The valve assembly must be installed where it is accessible for periodic
testing and maintenance. Clearances shown in the installation views
apply to exterior, interior and pit/vault installations and are only recom-
mendations. These minimums do not apply to removable protective
enclosures. Refer to local codes for actual requirements in your area.
4. PRIOR TO INSTALLING THE VALVE INTO THE LINE, FLUSH THE SUPPLY
LINE OF ALL FOREIGN MATERIAL. Failure to flush the supply line may
cause the check valves to become fouled and require disassembly and
cleaning.
5. Lift the assembly by connecting lift hooks to the lift rings cast into the
valve body. DO NOT LIFT THE ASSEMBLY BY CONNECTING TO THE
GATE VALVE HANDWHEELS OR STEMS.
6. After installation SLOWLY fill the assembly with water and bleed air from
the body using the # 3 and # 4 test cocks. Test the valve assembly to
ensure correct operation.
NOTE:
All assemblies are tested at the factory for proper operation and
leakage. If the valve does not pass the field test, it is most likely due to a
fouled check valve. This is not covered by the factory warranty. The valve
cover(s) must be removed and the check seats inspected and cleaned.
Any damage or improper operation caused by pipeline debris or improp-
er installation/start-up is not included in the factory warranty.
In case of a possible warranty claim, contact your local supplier or
FEBCO Representative. DO NOT REMOVE THE VALVE ASSEMBLY
FROM THE PIPELINE.
7. The assembly must be protected from freezing and excessive pressure
increases. Thermal expansion or water hammer can cause pressure
increases. These excessive pressure situations must be eliminated to
protect the valve and system from possible damage.
Typical Installation
Figure 1
Figure 2
Figure 3
IS-F-850/856-DC/DCDA
I N S T A L L A T I O N I N S T R U C T I O N S
Series 850, 856
Double Check Valve Assemblies
Double Check Detector Assemblies
Sizes: 2
1
⁄
2
" – 10" (65 – 250mm)
RWWP
FRT
4
175
850
12" Min (300mm)
Refer to Local Codes
6" Min (150mm)
Refer to Local Codes
Flow
HORIZONTAL INSTALLATION OR THE DC SERIES 850
(Front View, Shown With Strainer)
6" Min (150mm)
Refer to Local Codes
18" Min (450mm)
HORIZONTAL INSTALLATION OR THE DC SERIES 850
(Top View, Shown With Strainer)
6" Min (150mm)
Refer to Local Codes
18" Min (450mm)
VERTICAL INSTALLATION OR THE DC SERIES 850
(Shown With Strainer)
Flow
