8
3.
During heating cooling cycle open valves
C
and
D
, close
valves
A
and
B
.
A. Maintain a minimum clearance of one (1") inch to
hot water pipes. In air handling units where they
may be exposed to refrigerated air circulation, the
boiler piping system MUST be supplied with
fl
ow
control valves or other automatic means to prevent
gravity circulation of the boiler water during the
cooling cycle.
4.
Hot water boilers installed above radiation level must
be provided with a low water device either as part of
the boiler or at the time of boiler installation.
5.
When a boiler is connected to a heating system that
utilizes multiple zoned circulators, each circulator must
be supplied with a
fl
ow control valve to prevent gravity
circulation.
* Reduced pressure back
fl
ow preventer must be
present under provisions required by the Environmental
Protection Agency, (EPA).
6.
Bypass piping is an option which gives the ability to
adjust the supply boiler water temperature to
fi
t the
system or condition of the installation. Although, this
method of piping is not typically required for baseboard
heating systems.
A. This method is used to protect systems using
radiant panels and the material they are encased
in from high temperature supply water from the
boiler. See
Figure 7, Page 7
.
CONNECTING SUPPLY AND RETURN PIPING
B. This method is used to protect boilers from
condensate forming due to low temperature return
water. Generally noticed in large converted gravity
systems or other large water volume systems. See
Figure 8
.
C. This method is used to protect boilers from
condensate forming as well as protecting the
heating system from high water temperature. See
Figure 9, Page 9
.
7.
Note:
When using bypass piping, adjust valves
A
and
B
until desired system temperature is obtained.
8.
Bypass loop piping must be the same size piping for the
supply and return.
9.
Typical installation using circulators is shown in
Figure 10, Page 9
.
10.
Typical installation using zone valves is shown in
Figure 11, Page 10
.
11.
See
Figure 12, Page 10
for typical piping for domestic
hot water heater.
Figure 8 Bypass Piping Option For Converted Large Volume Systems
