Circulators; Hydronic Piping With Circulators, Zone Valves, And Multiple Boilers - Westinghouse WBMC**500 Manual

Expansion tanks must be sized according to total system
volume. This includes all length of pipe, all fixtures, boilers,
etc. Failure to properly size for system expansion could result
in wasted time, money, possible property damage, serious
injury, or death.
Undersized expansion tanks cause system water to be lost
from the relief valve, causing make-up water to be added.
Eventual boiler failure can result due to excessive make-
up water addition. SUCH FAILURE IS NOT COVERED BY
WARRANTY.
DO NOT install automatic air vents on closed type expansion
tank systems. Air must remain in the system and return to the
tank to provide an air cushion. An automatic air vent would
cause air to leave the system, resulting in improper operation
of the expansion tank.
Expansion Tank Sizing*
Model Heat Exchanger Volume (Gallons)
500
850
Table 2 - *Add Required Storage Tank Gallon Size to Heat
Exchanger Volume - 119 and 175 Gallon Tanks Available
2. The expansion tank must be located as shown in
Applications, this manual, or following recognized design
methods. See expansion tank manufacturer's instructions for
details. Always install an expansion tank designed for potable
water systems.
3. Connect the expansion tank to the air separator only if the
separator is on the suction side of the circulator. Always install
the system fill connection at the same point as the expansion
tank connection to the system.
4. Most chilled water systems are piped using a closed type
expansion tank.
Diaphragm (or Bladder) Expansion Tank
Always install an automatic air vent on top of the air separator
to remove residual air from the system.
E. Circulators
DO NOT use the boiler circulator in any location other than
the ones shown in this manual. The boiler circulator location
is selected to ensure adequate flow through the boiler.
Failure to comply with this caution could result in unreliable
performance and nuisance shutdowns from insufficient flow.
SIZING SPACE HEAT SYSTEM PIPING
1. In all diagrams, the space heating system is isolated from
the boiler loop by the primary/secondary connection.
2. Size the piping and components in the space heating system
using recognized design methods.
F. Hydronic Piping with Circulators, Zone Valves, and
Multiple Boilers
The boiler is designed to function in a closed loop hydronic
system. The included temperature and pressure gauge allows
the user to monitor system pressure and outlet temperature
from the boiler. It is important to note that the boiler has a
minimal amount of pressure drop that must be calculated
when sizing the circulators. Each boiler installation must have
an air elimination device that will remove air from the system.
Install the boiler so the gas ignition system components
are protected from water (dripping, spraying, etc.). Allow
clearance for basic service of the boiler circulator, valves, and
other components. Observe minimum 1" clearance around all
uninsulated hot water pipes when openings around pipes are
not protected by non-combustible materials.
On a boiler installed above radiation level, some states and
local codes require a low water cut off device. This is provided
standard on the boiler. Check with local codes for additional
requirements. If the boiler supplies hot water to heating coils in
air handler units, flow control valves or other devices must be
installed to prevent gravity circulation of boiler water in the coils
during the cooling cycle. Chilled water medium must be piped in
parallel with the boiler.
Freeze protection for new or existing systems must use glycol
specifically formulated for this purpose. This glycol must include
inhibitors that will prevent it from attacking metallic system
components. Make certain that the system fluid is checked for
the correct glycol concentration and inhibitor level. The system
should be tested at least once a year and as recommended by
4.2
the producer of the glycol solution. Allowance should be made
5.8
for the expansion of the glycol solution in the system piping.
Example: 50% by volume glycol solution expands 4.8% in
volume for the temperature increase from 32
water expands 3% over the same temperature rise.
Never use dielectric unions or galvanized steel fittings when
connecting to a stainless steel storage tank or boiler. Failure to
follow this instruction can lead to premature failure of the boiler
system. Such failures ARE NOT covered by warranty.
The boiler should not be operated as a potable hot water heater.
The boiler should not be used as a direct hot water heating
device.
15
o o
F to 180 F, while
WHL-033 Rev. 1.29.16