6
III. Water Piping and Trim
WARNING
Failure to properly pipe boiler may result in
improper operation and damage to boiler or
building.
A.
Design and install boiler and system piping
to
prevent oxygen contamination of boiler water.
Oxygen contamination sources are system leaks
requiring addition of makeup water, fittings, and
oxygen permeable materials in distribution system.
Eliminate oxygen contamination by repairing system
leaks, repairing fittings, and using non-permeable
materials in distribution system.
B.
Install circulator
with flanges, gaskets and bolts
provided.
C.
Install Safety Relief Valve.
See Figure 2. Safety Relief
Valve must be installed with spindle in vertical position.
WARNING
Safety relief valve discharge piping must be
piped near floor to eliminate potential of severe
burns. Do not pipe in any area where freezing
could occur. Do not install any shut-off valves.
D.
Connect system supply and return piping
to boiler.
Refer to Figures 2, 3, 4, & 5. Maintain minimum ½
inch clearance from hot water piping to combustible
materials.
E.
If boiler is used in connection with refrigeration
systems,
boiler must be installed with chilled medium
piped in parallel with the heating boiler using
appropriate valves to prevent chilled medium from
entering boiler. See Figure 3.
F.
If boiler is connected to heating coils
located in
air handling units where they may be exposed to
refrigerated air, boiler piping must be equipped with
flow control valves or other automatic means to prevent
gravity circulation of boiler water during operation of
cooling system.
G.
Use a boiler bypass
if the boiler is to be operated
in a system which has a large volume or excessive
radiation where low boiler water temperatures may be
encountered (i.e. converted gravity circulation system,
etc.).
Remove circulator and install pipe tee between
circulator and boiler return along with second tee in
supply piping as shown in Figures 4 and 5. Bypass
should be same size as the supply and return lines with
valves located in bypass and supply outlet as illustrated
in Figures 4 and 5 in order to regulate water flow to
maintain higher boiler water temperatures.
Set by-pass and boiler supply valves to half throttle
position to start. Operate boiler until system water
temperature reaches normal operating range.
Adjust valves to provide 180° to 200°F supply water
temperature. Opening the boiler supply valve will raise
system temperature, while opening by-pass valve will
lower system supply temperature.
H.
If it is required to perform a long term pressure
test
of the hydronic system, the boiler should first be
isolated to avoid a pressure loss due to the escape of air
trapped in the boiler.
To perform a long term pressure test including the
boiler, ALL trapped air must first be removed from the
boiler.
A loss of pressure during such a test, with no visible
water leakage, is an indication that the boiler contained
trapped air.
Figure 2: Near Boiler Piping
Figure 3: Recommended Piping for Combination
Heating & Cooling (Refrigeration) Systems
