Weil-McLain EG - Manual (Page 10)

Part Number 550-110-639/0703 10
EG, PEG, EGH G
AS
-
FIRED
B
OILERS
—
SERIES
4 — B
OILER
M
ANUAL
Piping connections
(continued)
2
Bypass piping
BYPASS PIPING IS NOT NORMALLY REQUIRED ON
ANY BASEBOARD SYSTEM
Bypass piping should be used for the following
installations. Bypass, supply, and return piping should
be same size.
1. See Figure 12 to protect:
• radiant panels, plaster, etc. from high temperature
water supplied from boiler, or
• boiler from condensation caused by low temperature
water returned from system.
2. See Figure 13 to protect boiler from condensation
formed by low water temperature returned from large
water content converted gravity systems, etc.
Use with refrigeration systems
The boiler must be installed so that chilled medium is
piped in parallel with the heating boiler with appropriate
valves to prevent the chilled medium from entering the
boiler. See Figure 14. Consult I=B=R Installation and
Piping Guides.
If boiler is connected to heating coils located in air handling
units where they can be exposed to refrigerated air, gravity
circulation during the cooling cycle must be prevented
with flow control valves or other automatic means.
8. Multiple Zoning
a) Zone valves:
Refer to zone valve manufacturer’s literature for wiring
and application. A separate transformer is required to
power zone valves.
Provide balancing valves to adjust the flow so it is about
the same in each zone.
b) Circulators:
Zoning with circulators requires a relay for each circulator.
Install flow control valves to prevent gravity circulation.
Provide balancing valves to adjust the flow so it is about
the same in each zone.
9. If system is to be ASME inspected and approved, an
additional high temperature limit is needed. Purchase
and install the control in supply outlet piping from
boiler.
Figure 12
Figure 13