System Piping - Dunkirk 3EW.65 Installation, Operation & Maintenance Manual

Installation of boiler for new heating system,
1.
Install all of radiation units (panels, radiators,
baseboard, or tubing) and supply and return mains
fi rst. After all heating system piping and components
have been installed, make fi nal connection of system
piping to boiler. It is recommended to mount circulating
pump on supply side piping, such that it pumps away
from expansion tank. Refer to fi gures on next pages.
Equip hot water boiler installed above radiation
2.
level with low water cut off device. Periodic inspection
is necessary, as is fl ushing of fl oat type devices, per
low water cut off manufacturer's specifi c instructions.
Packaged boiler is set up with 1¼" NPT supply
3.
and return piping from front of boiler. Boiler supply
and return piping can be moved to rear of boiler. Boiler
should not be piped return line to front, supply line
to rear, or vice versa, will cause boiler water to short
circuit heat exchanger. Piping connections may require
additional fi ttings and parts.
Install drain valve provided with boiler in return tee.
4.
See fi gure 6.
Install Safety Relief valve in rear section using ¾"
5.
nipple and street elbow provided with boiler. See fi gure
3.
A. Install safety relief valve with spindle in vertical
position.
B. Do not install shutoff valve between boiler and
safety relief valve.
C. Install discharge piping from safety relief valve.
• Use ¾" or larger pipe.
• Use pipe suitable for temperatures of 375°F
(191°C) or greater.
• Individual boiler discharge piping shall be
independent of other discharge piping.
• Size and arrange discharge piping to avoid
reducing safety relief valve relieving capacity
below minimum relief valve capacity stated on
rating plate.
• Run pipe as short and straight as possible to
location protecting user from scalding and properly
drain piping.
• Install union, if used, close to safety relief valve
outlet.
• Install elbow(s), if used, close to safety relief valve
outlet and downstream of union (if used).
• Terminate pipe with plain end (not threaded).

SYSTEM PIPING

Verify clean cold water supply is available when
6.
connecting to pressure reducing valve. When water
supply is from well or pump, a sand strainer should be
installed at the pump.
Low Design Water Temperature Systems (Below 140°
F) And Large Water Content Systems
• Signifi cant condensation may form in this boiler and/
or venting system if boiler is operated with return
temperatures of less than 120°F.
• Condensation is corrosive and can eventually cause
damage to boiler and venting system. Minimum design
return water temperature to prevent this condensation in
boiler and venting is 120°F.
• Boiler used in heating system where design water
temperatures below 140°F are desired (e.g. radiant fl oor
heating), a 3-way or 4-way mixing valve or suitable
alternative (e.g. Bypass Piping Arrangement shown
in diagram on following page) is required to prevent
low temperature (below return 120°F) return water
from entering boiler. When using mixing valve, follow
manufacturer's installation instructions.
• Boiler connected to system having large water content
(such as former gravity system), use of Bypass Piping
Arrangement shown in diagram on following page is
suggested.
Figure 6 - Safety Relief Valve Installation
9
Follow Instructions
to install discharge
piping from safety
relief valve to drain.