Weil-McLain Gold CGi Series 2 User Manual page 28

GOLD
4f
System-bypass
piping method
Valve adjustment
28
CGi Series 2 Gas-Fired Water Boiler
Water piping —
This piping method is called a
the system (through valve
cooler system return water temperature in order to provide minimum 130 °F return water to
the boiler. Valve 7b will most often be full open, but may need to be slightly closed on some
low pressure drop systems in order to cause enough flow through valve
is an alternative piping method that provides return water temperature control for
Figure 24
boilers installed on
converted gravity systems
apply the piping of
Do not
regulating the water temperature provided to the system and could result in excessive water
temperature in the radiant tubing.
System-bypass piping as shown in
zoning. When used with circulator zoning however, the boiler circulator (item
piped as shown. It cannot be used as one of the zoning circulators.
Do not apply system-bypass piping if the reduced flow in the system could cause poor heat
distribution. That is, system-bypass piping reduces the flow in the system and increases the
water temperature supplied to the system. This can cause increased heat from radiators at the
beginning of the system and reduced heat from radiators near the end of the system.
1. Start with valve fully closed and
7a
2. Gradually open valve
least 130 °F at all times.
3. Valve regulates the amount of boiler supply water mixed with return water. Valve
7a
causes a pressure drop in the system needed to balance flow through valve
system.
4. The valve adjustment should be done with the system at the coldest expected temperature
(60 °F for converted gravity systems or high mass radiant systems).
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 bypasses
system-bypass
). This bypassed hot water from the boiler outlet mixes with
7a
(large water content or steam systems).
on
Figure 24 radiant heating systems
can be used with either zone valve or circulator
Figure 24
fully open.
7b
while closing valve until the temperature at gauge
7a 7b
system supply temperature
system supply temperature
provide controls and piping
regardless of system supply temperature. Contact
no less than 130 °F
.
7a
. It provides no method
3
7a
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
), must be
reads at
8
7b
and the
injection
outdoor