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Installation & Operation Manual
5 Hydronic piping
Please note that these illustrations are meant to show system piping concept only, the installer is responsible
for all equipment and detailing required by local codes.
NOTICE
HOT WATER
GENERATOR
WATER
GENERATOR
CIRCULATOR
BOILER PUMP
(TYPICAL) FLOW CHECK
VALVE (TYPICAL)
Y-STRAINER
(RECOMMENDED)
RELIEF
VALVE
BALL VALVE
(TYPICAL)
AIR SEPARATOR
DRAIN PORT
(TYPICAL)
SYSTEM
CIRCULATOR
BACK FLOW
PREVENTER
PRESSURE
REDUCING VALVE
PRESSURE
GAUGE
EXPANSION
TANK
FROM SYSTEM
TO SYSTEM
MAKE UP
WATER
BOILER DRAIN
(TYPICAL)
SYSTEM RETURN
SENSOR
SYSTEM SUPPLY
SENSOR
Figure 5-3 Multiple Boilers - Common Header - Recommended - Primary / Secondary Flow

Model Number of Units

234567 8

Recommended Common Header Pipe Sizes in Inches

FB 1500 445566 7
FB 2000 455677 8
FB 2500 556778 10
FB 3000 567781010
FB 3500 5 6 7 8 10 10 10
NOTICE A system supply sensor (factory supplied) MUST BE installed for proper boiler operation.
Table 5C Multiple Boilers - Common Header - Primary / Secondary Flow
System flow should always remain higher than the required flow for the boiler(s) when the boiler(s) is in
operation to prevent short cycling and high limit issues.
NOTICE
[Based on a boiler ΔT of 30°F.]