2
Feature and Operating Procedures
MAINTENANCE MANUAL SERIES 850, 856, 870V & 876V 2
1
⁄
2
"- 10" (65 – 250mm)
Double Check Valve Assembly Operation
The FEBCO Double Check Valve Assemblies consist of two indepen-
dently operating, spring loaded check valves . The pressure drop across
the first check valve is approximately 1 .0 psig with no flow . The pressure
drop across the second check valve is also 1 .0 psig with no flow .
A complete assembly includes two shutoff valves and four test cocks .
NOTE:
The 870V and 876V, when installed in the vertical orientation,
must include vertical support under the second check body section .
Double Check Detector Assemblies
Bypass Operation
All low flow demands up to a minimum of three GPM are to pass only
through the bypass assembly .
All flows above three GPM will pass through both the bypass and main-
line valve without accurate meter registration .
How to Order Parts/Repair Kits
1) Locate item number and kit number in this maintenance manual .
2) Verify the size of the valve the parts are to be used on .
3) Provide full model number located on I .D . plate .
4) Give kit number .
5) A serial number (located on the I .D . plate) will assist in ordering
the proper kits .
6) Contact your local FEBCO Parts Distributor .