User Guide

Feature and Operating Procedures

MAINTENANCE MANUAL SERIES 850, 856, 870V & 876V 2

⁄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.