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Installation & Operation Manual
38
EXPANSION
TANK
AIR SEPARATOR
PRESSURE REDUCING
VALVE
BACK FLOW
PREVENTER
BALL VALVE
(TYPICAL)
UNION (TYPICAL)
PRESSURE RELIEF VALVE
FLOW CHECK
VALVE (TYPICAL)
INDIRECT DHW
TANK
BOILER 1
(LEADER)
TEMPERATURE /
PRESSURE GAUGE
PRESSURE GAUGE
DRAIN
DRAIN POINT
(TYPICAL)
BOILER CIRCULATOR
(TYPICAL)
ANTI-SCALD
MIXING VALVE
SYSTEM SUPPLY SENSOR
SYSTEM CIRCULATOR
TO SYSTEM
FROM SYSTEM
BOILER 2
(MEMBER 1)
BOILER 3
(MEMBER 2)
BOILER 4
(MEMBER 3)
DOMESTIC
HOT WATER
CIRCULATOR
COLD WATER IN
HOT WATER OUT
MAKE UP WATER
NOT TO EXCEED 4 PIPE DIAMETERS
OR A MAXIMUM OF 12” APART
Figure 6-8 Multiple Boilers - Primary/Secondary Piping
Model
Number of Units
2 3 4 5 6 7 8
Manifold Pipe Sizes in Inches (mm)
399
2 1/2 (64) 3 (76) 3 1/2 (89) 4 (102) 4 (102) 5 (127) 6 (152)
500
3 (76) 3 1/2 (89) 4 (102) 5 (127) 5 (127) 6 (152) 6 (152)
600
3 1/2 (89) 4 (102) 5 (127) 5 (127) 6 (152) 6 (152) 8 (203)
700
3 1/2 (89) 5 (127) 5 (127) 6 (152) 6 (152) 8 (203) 8 (203)
800
4 (102) 5 (127) 5 (127) 6 (152) 8 (203) 8 (203) 8 (203)
NOTICE
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.
6 Hydronic piping