Columbia CDVB SERIES, Installation, Operation & Maintanance Manual, Page: 9 / 28

9
CONNECTING SUPPLY & RETURN PIPING
Connect supply and return piping as suggested in
1. figure
#5
, when the boiler is used in connection with refriger-
ated systems.
The chilled medium MUST BE PIPED IN PARALLEL A.
with the boiler.
Use appropriate valves to prevent the chilled medium B.
from entering the heating boiler.
During heating cycle open valves A and B, close I.
valves C and D.
During cooling cycle, open valves C and D, close II.
valves A and B.
C. Maintain a minimum clearance of one inch to hot C.
water pipes.
When the boiler is connected to heating coils located in
2.
air handling units where they may be exposed to refrig -
erated air circulation, the boiler piping system MUST
BE supplied with flow control valves or other automatic
means to prevent gravity circulation of the boiler water
during the cooling cycle.
Hot water boilers installed above radiation level must be
3.
provided with a low water cut-off device.
When a boiler is connected to a heating system that
4.
utilizes multiple zoned circulators, each circulator must
be supplied with a flow control valve to prevent gravity
circulation.
Hot water boilers and system must be filled with water
5.
and maintained to a minimum pressure of 12 pounds per
square inch.
Bypass piping is an option which gives the ability to adjust
6.
the supply boiler water temperature to fit the system or
the condition of the installation. This method of piping,
however, is not typically required for baseboard heat -
ing systems. Typical installations where bypass piping is
used are as follows:
This method is used to protect boilers from conden - A.
sation forming due to low temperature return water.
Generally noticed in large converted gravity systems or
other large water volume systems. See
figure #6
.
This method is used to protect systems using radiant B.
panels and the material they are encased in from high
temperature supply water from the boiler. And protect
the boiler from condensate. See
figure #7
and
#8
.
IMPORTANT: Circulators in the following
illustrations are mounted on the system supply
side, but mounting on the system return side is
also acceptable practice.
CIRCULATOR
VALVE
EXPANSION
TANK
VALVE
RETURN
SUPPLY
12"
MAX.
CIRCULATOR
FLOW
VALVE
SYSTEM
TEMPERATURE
GAUGE
"B"
"A"
SYSTEM
PRIMARY
6"
FEED
WATER
Figure #5
ZONE
CIR.
VALVE
FLOW
VALVE
EXPANSION
TANK
VALVE
SYSTEM
TEMPERATURE
GAUGE
RETURN
SUPPLY
"A"
"B"
6"
FEED
WATER
BYPass PiPinG
Figure #6
6"
EXPANSION
TANK
TEMPERATURE
SYSTEM
GAUGE
SUPPLY
RETURN
4 WAY MIXING
VALVE
ZONE
CIR.
WATER
FEED
MiXinG ValVe PiPinG
Figure #7