Patterson-Kelley Thermific, Инструкция по установке и эксплуатации

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Thermific
®
Gas-Fired Boiler Installation
Page 12
Piping With Air Handling Units
The boiler piping system of a hot water heating boiler
connected to heating coils located in air handling units,
where they may be exposed to refrigerated air circula-
tion, must be equipped with flow control valves or
other automatic means to prevent gravity circulation of
the boiler water during the cooling cycle.
3.8.2 Boiler Inlet and Outlet Connections
Union
Isolating
Valve
Relief Valve
Drain
Union
Isolating
Valve
Boiler
Drain
Strainer
Outlet
(to system)
Isolating
Valve
Inlet
(from system)
Boiler Inlet and Outlet Connections
Make water connections as the application warrants, or
at a minimum, as shown, but always in compliance
with the local requirements.
Note: Pipe unions and isolating valves must be in-
stalled in both water connections for ease of service.
The bottom connection to the boiler is the INLET and
must be used for the return from the system.
The top connection to the boiler is the OUTLET and
must be connected as the supply to the system.
3.8.3 Boiler Water Piping by Installer
Strainer
To avoid possible contamination of the boiler with
dirt, rust or sediment from the system, a strainer near
the boiler inlet is strongly recommended. Even new
systems may contain sufficient foreign material to
eventually reduce the performance of the heat ex-
changer. Adequate circulation of good clean water is
essential to maximum efficiency and long life of the
boiler.
Relief Valve and Piping
Each boiler is supplied with a pressure-relief valve
sized in accordance with ASME requirements. The
relief valve should be piped to a suitable floor drain.
Reducing couplings or other restrictions are not per-
mitted in the discharge line.
Low Water Cut-off
The boiler is furnished with a flow-switch-type low
water cut-off; no field piping is required. If the flow
switch does not sense water flow, the boiler will shut
down and a red indicator will be illuminated on the
control panel.
WARNING!
Never install a valve that can isolate the low water cut-
off from the boiler.
Installation of an external low water cutoff or manual
reset low-water switch may be required by certain
codes or in certain installations. Consult the factory
for details.
Drain Valve and Piping
The boiler is not provided with external drain connec-
tions. A drain valve should be installed near the inlet
(system return) connection to the boiler and piped to a
suitable floor drain. The boiler can be completely
drained through the bottom header by removing the
flush plug in the bottom end plate.
This plug may also be used to flush accumulated
sediment from the bottom of the boiler.