Weil-McLain CGS-4E Boiler User Manual


  Open as PDF
of 64
 
Part number 550-110-282/1108
22
GOLD
CGs-4E Gas-Fired Water Boiler — Boiler Manual
Failure to prevent low return water temperature to the boiler could cause corrosion of
the boiler sections or burners, resulting in severe personal injury, death or substantial
property damage.
Radiant heating system piping should include a means of regulating the boiler return
water temperature
and the system supply temperature (such as provided by an injec-
tion pumping control
).
Boilerreturnwatertemperaturewillbeadequatelycontrolledusingthemethodsshown
in this manual provided the system supply temperature is relatively constant.
DO NOT apply the methods of this manual if the system is equipped with an outdoor
reset control.
Instead, provide controls and piping which can regulate the boiler re-
turn water temperature
at no less than 130°F regardless of system supply temperature.
ContactyourWeil-McLainrepresentativeforsuggestedpipingandcontrolmethods.
Failure to prevent cold return water temperature to the boiler could cause corrosion
damage to the sections or burners, resulting in possible severe personal injury, death or
substantial property damage.
3d Piping — low temp systems (continued)
SYSTEM-bypass piping
method
This piping method (Figure 12, page 23) is called a sys-
tem-bypass
because part of the circulator flow bypasses
the system (through valve 7a). This bypassed hot water
from the boiler outlet mixes with 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 7a.
Figure 12 is an alternative piping method that provides
return water temperature control for boilers installed
on converted gravity systems (large water content or
steam systems).
Do not apply the piping of Figure 12 on radiant heat-
ing systems
. It provides no method 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
Figure 12 can be used
with either zone valve or circulator zoning. When used
with circulator zoning however, the boiler circulator
(item
3), must be piped as shown. It cannot be used as
one of the zoning circulators.
Donotapplysystem-bypasspipingifthereducedow
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.
Valve adjustment
1. Startwithvalve7a fully closed and 7b fully open.
2. Graduallyopenvalve
7a while closing valve 7b until
the temperature at gauge 8 readsatleast130°Fatall
times.
3. Valve
7a regulates the amount of boiler supply water
mixedwithreturnwater.Valve7b causes a pressure
drop in the system needed to balance flow through
valve 7a and the 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).
 previous next