Lochinvar 000 - 500 사용자 설명서
FIG. 43 Primary/Secondary Piping of a Single Boiler
Heating boilers with inputs of 315,000 - 500,000 Btu/hr
or larg er installed on multiple zone systems are rec om -
mend ed to be installed with a primary/sec ond ary piping
sys
or larg er installed on multiple zone systems are rec om -
mend ed to be installed with a primary/sec ond ary piping
sys
tem as shown in Figure 43. A pri
ma
ry/secondary
pip
ing system may also be in
stalled on smaller input
boil ers to ensure proper boiler flow rates. Primary/sec -
ond ary piping is also ideal for systems using a mixture of
propylene glycol and water. A primary/secondary piping
system uses a dedicated pump to supply flow to the
boiler only. This pump is sized based on de sired boiler
flow rate, boiler head loss and head loss in the sec ond ary
system piping only. The secondary pump, in stalled in
the boiler piping, ensures a constant wa ter flow rate to
the boiler for proper operation. Boiler installation with a
primary/secondary piping sys
ond ary piping is also ideal for systems using a mixture of
propylene glycol and water. A primary/secondary piping
system uses a dedicated pump to supply flow to the
boiler only. This pump is sized based on de sired boiler
flow rate, boiler head loss and head loss in the sec ond ary
system piping only. The secondary pump, in stalled in
the boiler piping, ensures a constant wa ter flow rate to
the boiler for proper operation. Boiler installation with a
primary/secondary piping sys
tem can prevent noise
problems caused by low sys
tem water flows. A
primary/secondary piping system is recommended on
any boiler where low water flow conditions may present
an operational problem.
any boiler where low water flow conditions may present
an operational problem.
A primary/secondary piping system is ideal for sys tems
filled with a propylene glycol and water mix ture. A
glycol and water mixture is more dense than water only
and may result in a lower boiler flow rate. A lower
boiler flow may cause noise on operation or short
cycling of the burners. A larger secondary pump may
be used on a primary/sec ond ary system to pro vide an
increased boiler flow rate. A glycol and water system
may require from 10 to 20% more flow to compensate
for the in creased density of the glycol and its effect on
the heat transfer process in the boiler. The exact
in crease in flow that may be required is based on the
type and percentage of glycol added to the boiler
system. Consult the manufacturer of the glycol for
additional recommendations when using a gly col and
water fill for your boiler system.
filled with a propylene glycol and water mix ture. A
glycol and water mixture is more dense than water only
and may result in a lower boiler flow rate. A lower
boiler flow may cause noise on operation or short
cycling of the burners. A larger secondary pump may
be used on a primary/sec ond ary system to pro vide an
increased boiler flow rate. A glycol and water system
may require from 10 to 20% more flow to compensate
for the in creased density of the glycol and its effect on
the heat transfer process in the boiler. The exact
in crease in flow that may be required is based on the
type and percentage of glycol added to the boiler
system. Consult the manufacturer of the glycol for
additional recommendations when using a gly col and
water fill for your boiler system.
The installer must ensure that the boiler has ad e quate
flow without excessive temperature rise. The
tem per a ture rise on a multiple zone system should be
made when only the zone with the longest length and/or
high est head loss is open. Low system flow 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. These conditions indicate the
need to open the bypass adjustment valve, in stal la tion
of a larger circulator pump or installation of the boiler
with a primary/secondary piping system. Sys tem noise
may also indicate an oversized boiler.
flow without excessive temperature rise. The
tem per a ture rise on a multiple zone system should be
made when only the zone with the longest length and/or
high est head loss is open. Low system flow 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. These conditions indicate the
need to open the bypass adjustment valve, in stal la tion
of a larger circulator pump or installation of the boiler
with a primary/secondary piping system. Sys tem noise
may also indicate an oversized boiler.
FIG. 44 Boiler with Low Temperature Bypass Piping - Models
315,000 - 500,000 Btu/hr
315,000 - 500,000 Btu/hr
A boiler operated with an inlet temperature of less than
140°F (60°C) must have a bypass to prevent problems
with condensation. A bypass as shown in Figure 44
must be piped into the system at the time of installation.
140°F (60°C) must have a bypass to prevent problems
with condensation. A bypass as shown in Figure 44
must be piped into the system at the time of installation.
34
At no time should the system pressure be less than
12 PSIG.
CAUTION
12"
BYPASS
FROM
SYSTEM
SYSTEM
AIR SEPARATOR
LWCO
(OPTIONAL)
(OPTIONAL)
SECONDARY
BOILER PUMP
BOILER PUMP
EXPANSION TANK
PRV
SYSTEM
PUMP
PUMP
TO SYSTEM
MAKE-UP
WATER
WATER
PRIMARY/SECONDARY
BOILER PIPING