Weil-McLain WM97+110, Руководство пользователя, Страница: 41 / 132

Part number 550-142-085/0712
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WM97+
gas
-
fired water boiler
— Boiler Manual
Expansion tank — WM97+155
Figure 44 WM97+155
external expansion tank
piping, diaphragm or bladder-type
Figure 45 WM97+155
external expansion tank
piping, closed-type expansion tank
LEGEND for Figure 44 and Figure 45
1 WM97+ boiler
3 Relief valve, supplied with boiler, field piped —
MUST be piped to boiler supply connection — see
page 13 for information
4 Relief valve piping to drain — see page 37
6 Isolation valves
8 System expansion tank, diaphragm type, when
used
9 Air separator
10 Flow/check valve (in boiler circulator)
11 Purge/drain valves
12 Boiler circulator
14 Primary/secondary by-pass valve — see page 39
for information
15 System expansion tank, closed-type, when used
20 Make-up water supply
23 Backflow preventer, when used
25 Pressure reducing valve, when used
27 Quick-fill valve, when used
28 DHW boiler water supply connection, when used
— see page 13 for information
29 DHW boiler water return connection, when used
— see page 13 for information
30 Pressure/temperature gauge, supplied with
boiler, field piped
31 System circulator, supplied by installer
Expansion tank
Figure 44 and Figure 45 show typical installations of the system expansion tank. Always
locate the air separator and expansion tank as shown in the suggested piping drawings,
beginning on page 45.
Ensure that the expansion tank size will handle boiler and system water volume and
temperature. See tank manufacturer’s instructions and ratings for details. Additional
tanks may be added to the system if needed to handle the expansion. These tanks may
be installed by connecting to tees in the system piping.
Undersized expansion tanks
cause system water to be lost from the
relief valve and makeup water to be added through the fill valve. Eventual
boiler failure can result due to excessive make-up water addition. Always
locate the
cold water fill connection
at the expansion tank. Never
locate this elsewhere in the system.
Diaphragm- or bladder-type tank:
Refer to Figure 44 for suggested piping when using a diaphragm- or bladder-type
expansion tank.
Diaphragm- or bladder-type expansion tank
— Control
fill pres-
sure
with the tank air charge pressure. Always check pressure and charge
tank
with tank removed from system
to be sure reading is accurate.
Boiler relief valve is set for 30 PSIG. Operating pressure of system, after
temperature expansion above cold fill pressure, should not exceed 24 PSIG
to avoid weeping of relief valve.
Install an
automatic air vent
on top of the air separator, per separator manufacturer’s
instructions.
Closed-type expansion tank:
DO NOT use a closed-type tank if connecting to a water heater that is
equipped with an automatic air vent.
Figure 45 shows suggested piping when using a closed-type expansion tank, in which
the air is directly in contact with tank water.
Connect piping (½” or ¾”) from the air separator top outlet to the tank fitting. Slope
any horizontal piping a minimum of 1 inch per 5 feet of horizontal pipe.
Always use a
tank fitting
, such as the B&G Tanktrol or Taco Taco-Trol (shown). The
fitting reduces gravity flow of water in the piping to the tank, avoids air bubbling through
the tank water, and provides the proper fill height in the tank.
Correct all leaks
in the system or tank piping. Leaks allow air to escape
from the system and will cause water-logging of the tank. This will result
in water loss through the boiler relief valve due to over-pressurization.
NEVER
use an automatic air vent in a system equipped with a closed-
type expansion tank. The air removed from the system will cause water-
logging of the expansion tank.
Closed-type expansion tank
— Follow tank manufacturer’s instruc-
tions for
filling the tank
. Typical tank sizing provides for approximately
12 PSIG when the tank is filled to the normal level and system water is
cold. Note that boiler relief valve is set for 30 PSIG. Operating pressure
of system, after temperature expansion above cold fill pressure, should
not exceed 24 PSIG to avoid weeping of relief valve.