Weil-McLain Gold CGi Series 2 User Manual page 26

GOLD
4e
Boiler-bypass
piping method
Temperature
gauges
Valve adjustment
26
CGi Series 2 Gas-Fired Water Boiler
Water piping —
This piping method is called a
around the boiler (through valve
boiler, in order to raise the average water temperature in the boiler enough to prevent flue gas
condensation. Boiler-bypass piping is effective for some boilers — including the CGi —
provided the flow rates are adjusted according to the instructions following.
are alternative piping suggestions for
Figures 22 and 23
or steam systems) or
radiant heating system
can't be applied. (
Figure 24
bypass piping.
Figure 24
does not protect the radiant system from possible high water temperature.)
Boiler-bypass piping keeps system flow rate as high as possible and temperature drop as low
as possible, helping to equalize the building heat distribution.
Gauge 4a is optional if the bypass valves will be adjusted using cold (or room temperature)
return water to the boiler. (When setting the valves without gauge
or room temperature water — assume the return water temperature to be 60 °F. Set the valves
so gauge reads at least 120 °F.
8
Gauge is optional on converted gravity systems, but
4b
— to display the water temperature being supplied to the radiant tubing.
Gauge is on all systems to assure reliable adjustment of the bypass valves. The
8 required
boiler-mounted temperature/pressure gauge can be used if a separate temperature gauge is
not installed.
1. Start with valve fully closed and
7a
2. Gradually open valve
60 °F higher than gauge
a low enough flow rate and high enough average temperature to prevent condensation
even with low system return water temperature.
3. Valve regulates the system flow rate, while valve
7a
4. The boiler-mounted temperature/pressure gauge may be used in place of a separate
gauge .
8
Failure to
prevent low return water temperature
the boiler sections or burners, resulting in severe personal injury, death or substantial property
damage.
Radiant heating system piping should include a means of
and the
water temperature
).
pumping control
Boiler return water temperature will be adequately controlled using the methods shown in
this manual provided the
apply the methods of this manual if the system is equipped with an
DO NOT
. Instead,
reset control
at
water temperature
your Weil-McLain representative for suggested piping and control methods.
Failure to
prevent cold return water temperature
damage to the sections or burners, resulting in possible severe personal injury, death or
substantial property damage.
low temp systems
because part of the circulator flow is bypassed
boiler-bypass
). This method reduces the flow rate throughout the
7a
— for use when primary/secondary piping
is another alternative, using system bypass in place of boiler-
however, is not suitable for radiant heating applications because it
fully open.
7b
while closing valve
7a 7b
. A minimum 60 °F temperature rise through the boiler assures
4a
system supply temperature
system supply temperature
provide controls and piping
regardless of system supply temperature. Contact
no less than 130 °F
(large water content
converted gravity
installed — using cold
4a
on radiant heating systems
required
until the temperature at gauge
regulates the boiler flow rate.
7b
to the boiler could cause corrosion of
regulating the boiler return
(such as provided by an
is .
relatively constant
which can
regulate the boiler return
to the boiler could cause corrosion
Part Number 550-110-710/0200
reads
8
injection
outdoor