Lochinvar EFFICIENCY PLUS, Руководство дизайнера

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16 L o c h i n v a r
D E S I G N E R
’
S G U I D E E F F I C I E N C Y
+
B O I L E R
6 1 5 - 8 8 9 - 8 9 0 0
Lochinvar
Three Way Valves
The installation of a three-way valve in a
hydronic heating application is not generally
recommended, as most piping methods allow
the three-way valve to vary flow through the
boiler. This variable flow through the boiler is not
recommended, as it alters heat transfer speed
and places undue heat stresses on the heat
exchanger surface. Additionally, low flow rates
can result in overheating of the boiler water,
which can cause short burner on cycles, system
noise and in extreme cases, a knocking flash to
steam. For these reasons, constant circulation is
recommended to maintain proper operation
while the boiler is firing.
Water Flow Switch
Due to the low water content (between 1 and 6
gallons) of the copper finned tube heat
exchanger, a flow switch is available for use as a
low water cutoff device on all models. The flow
switch should be installed in the outlet piping of
the boiler and wired into the ignition system. Per
ASME CSD1 and in most localities, a flow switch
is accepted as a low water cutoff for boilers
requiring forced circulation. (See CSD1 CW-210,
Part A) It is prudent to verify preference with the
local code official.
A specially sealed flow switch and conduit are
furnished for outdoor installations.
Low Water Cut-off
If this boiler is installed above radiation level, a
low water cut-off device
must be installed at the
time of boiler installation (option available from
factory).
Relief Valve Piping
This boiler is supplied with a pressure relief
valve(s) sized in accordance with
ASME Boiler
and Pressure Vessel Code, Section IV “Heating
Boilers”.
Low Flow Systems
When the system flow rate is less than the
minimum flow required for proper boiler
operation, the Eff boiler should be
installed with a primary/secondary piping
system.
This will allow the installation of a secondary-
circulating pump sized specifically to provide
a higher flow rate through the boiler and the
secondary loop piping to ensure proper
operation. See “Primary/Secondary Piping”
for installation and piping requirements.
IMPORTANT!
Operation of this boiler
on a low temperature
system requires special
piping to ensure correct
operation. Consult “Low
Water Temperature
System” section for
piping details.
(FIG. 15) PRIMARY/SECONDARY SYSTEM PIPING
HEATING SUPPLY
LOOP
*12” MAX
TO FLOOR
DRAIN
MAKE-UP WATER
LIT0476
HEATING RETURN LOOP
(TABLE K) – HEAT EXCHANGER
HEAD-LOSS CURVE