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XI. Hot Water Supply Boiler Piping (continued)
b. The safety relief valve must be installed with the
spindle in a vertical position. Installation of the
relief valve must comply with ASME Boiler and
Pressure Vessel Code, Section IV.
c. If the safety relief valve is to be replaced, the
replacement valve must have a relief capacity
equal or exceeding the minimum relief valve
capacity shown on the heat exchanger ASME
plate. Also, when replacing the safety relief valve,
verify the temperature and pressure gauge meets
ASME requirements for the replacement safety
relief valve.
d. Pipe the safety relief valve discharge to a location
where hot water or steam will not cre ate hazard
or property damage if the valve discharges. The
end of the discharge pipe must terminate in an
untreated pipe.
e. If the safety relief valve is not piped to a drain,
it must terminate at least 6 in. (150mm) above
the floor. Do not run safety relief valve discharge
pipe through an area prone to freezing. The
termination of discharge piping must be in an
area where it will not became plugged by debris.
f.
The storage tank requires its own T&P relief
valve installed according to the manufacturers
instructions.
3. Drain Valves
A factory installed 3/4" NPT drain valve and
connection is provided with the unit.
4. Flow Switch (Factory Supplied)
This appliance is CSD-1 compliant and equipped
with water flow switch and reset low water cut out
box. A flow switch is required for forced circulation
coil-type water boilers to prevent overheating
and the heat exchanger failure in accordance with
requirements of ASME Boiler and Pressure Vessel
Code, Section IV, and ANSI/ASME CSD-1 "Controls
and Safety Devices for Automatically Fired Boilers".
5. Circulator Pump (Required)
A pump is required to circulate the water between
the storage tank and the appliance. It is the
responsibility of the installer to size and install the
circulator for the proper flow rate and temperature
rise. Refer to Table 28 and Table 29.
6. Expansion Tank (Required)
If this appliance is replacing an existing appliance
with no other changes in the system, the old
expansion tank can generally be reused. If the
expansion tank must be replaced, consult the
expansion tank manufacturer's literature for proper
sizing.
7. Y-strainer (Recommended)
!
Safety Relief Valve
Burn Hazard. Safety relief valve discharge shall
be piped in such a way to prevent or eliminate
potential burn risk.
DO NOT pipe in any area where freezing could
occur.
DO NOT install any shut-off valves, plugs, caps, or
reducers in the discharge piping.
Discharge line shall be installed to allow complete
drainage of both the valve and the line.
Consult local codes for proper discharge pipe
arrangement.
Observe a minimum of 1/2 inch (12 mm) clearance
around all uninsulated hot water piping.
A Y-strainer or equivalent strainer removes heating
system debris from the hydronic system and
protects the heat exchanger. Install the strainer
in the primary piping going to the inlet of the
appliance.
8. Isolation Valves (Recommended)
Isolation valves are useful for servicing and stopping
water flow in the case of failure. Full port ball valves
are required.
9. Mixing Valve/Anti-scald Valve (Recommended)
A mixing valve is recommended when storing water
at scalding hot temperatures.
10. Recirculation Filter (Recommended)
A Recirculation filter can capture suspended solids
in the system and help prevent the effects of
erosion corrosion.
D. Scalding
This appliance can supply water at scalding
temperatures to faucets and other fixtures in the
system. Mixing valves are recommended to maintain
the supply water at safe temperatures.
1. Maintaining the storage tank above 140 0F and
using a mixing valve can increase the amount of
hot water available and help prevent the growth
of water borne bacteria like Legionella.
50
WARNING
WARNING
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