NFPA 13, 2010
8.17.4.6* Backflow Devices
8.17.4.6.1* Backflow Prevention Valves. Means shall be provided
downstream of all backflow prevention valves for flow
tests at system demand.
A.8.17.4.6.1 The full flow test of the backflow prevention
valve can be performed with a test header or other connection
downstream of the valve. A bypass around the check valve in
the fire department connector line with a control valve in the
normally closed position can be an acceptable arrangement.
When flow to a visible drain cannot be accomplished, closed
loop flow can be acceptable if a flowmeter or site glass is incorporated
into the system to ensure flow. When a backflow prevention
device is retroactively installed on a pipe schedule system,
the revised hydraulic calculation still follows the pipe
schedule method of 11.2.2 with the inclusion of friction loss
for the device.
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