Bell & Gossett V57083D Diaphragm Expansion Tanks ASME And Non-Code - Manual (Page 3)

C. Installation ( “HFT” Series)
The series “HFT” may be installed into a tee or any other suit-
able tapping on a water heating system, preferably on the
suction side of the circulator. (see Figure 2).
SYSTEM VENTING AND PURGING
(For hydronic heating systems not
potable water systems)
After initial venting and purging of air from the system, more
air will be released from the water as it is heated. Therefore, it
is recommended that a B&G air separator be installed on the
main.
If the system has multiple loops or zones, the supply water for
all loops and zones must pass through the air separator for
complete and continuous air removal. In case the piping
arrangement does not permit the installation of a single air
separator on the main, air separators should be installed on
each loop or zone. In this event, only one expansion tank is
required for the system.
Even with a B&G air separator installed on the main or mains,
it is recommended that B&G air vents be installed on high
points in the system.
It is also recommended that manual (key or coin type) air
vents be installed at higher points on the radiation.
D. Installation ( “WTX”, “WT” & “WTA” Series)
The well tank should be installed as close as possible to the
pressure switch. Inline models are generally installed directly
into the main water supply with a
3 /
4
" connection. The floor
models are generally installed using a tee off main. (See fig-
ures 3 & 4.) The air pressure should be adjusted to 1-2 PSIG
below the pressure switch pump “cut-in” setting. (Tank should
be at room temperature and empty of water when adjusting
the air pressure.) Refer to Table 1 for the factory pre-charge
pressure.
System Connection
1. Locate desired tank location.
2. Level the tank as necessary.
3. Connect to pump supply line with the same size pipe as
from pump.
4. All piping should be in accordance with local code require-
ments
OPERATING INSTRUCTIONS
1. The expansion tank’s sealed-in-air pre-charge prevents
water from entering the tank until the system pressure
exceeds the pre-charge pressure.
2. As the water temperature rises, expanded water enters the
expansion tanks water reservoir. The pre-charged air
chamber absorbs the pressure increase, keeping system
pressures below the relief valve setting.
3. As water is used in a potable well system, the pressure in
the air chamber forces water back into the system until the
pressure switch pump “cut-in” setting is reached. The
pump will then turn on forcing water into the tank until the
pump “cut-out” pressure is reached. The water stored in
the tank is supplied to the potable water system under
pressure without the pump turning on.
3
TYPICAL INSTALLATION
FIGURE 2
B&G PRESSURE
REDUCING VALVE
CW FILL
SHUT-OFF
VALVE
B&G RELIEF
VALVE DIAPHRAGM TYPE
EXPANSION TANK
“HFT”
B&G BOOSTER
FLO-CONTROL B&G
VALVE
TO
SYSTEM
BOILER
RETURN
OPTIONAL SIDE
OUTLET BOILER
CONNECTION
AIR SEPARATOR
FLOW
INLINE
WELL
TANK
TO SYSTEM
PRESSURE
SWITCH
FROM WELL
FLOOR
MOUNT
WELL
TANK
RELIEF VALVE
TO SYSTEM
DRAIN
PRESSURE
SWITCH
TO WELL
TANK
PRESSURE
GAUGE
RELIEF
VALVE
DRAIN
PRESSURE
SWITCH
SUBMERSIBLE
PUMP
INSTALLATION WITH JET PUMP
FIGURE 3
INSTALLATION WITH SUBMERSIBLE PUMP
FIGURE 4