Bell & Gossett HFT Expansion Tanks for Hydronic Heating Systems - Manual (Page 2)

INSTALLATION INSTRUCTIONS
A. PRE-INSTALLATION
1. Visually inspect expansion tank and check for damage
prior to installation.
WARNING: If the expansion tank is
damaged, it must be replaced. Failure to
follow this instruction may result in serious
personal injury or death and property
damage.
2. Bell & Gossett Series HFT diaphragm tanks are factory
pre-charged to 12 PSI. Adjust pre-charge to equal system
fill pressure.
3. Replace and tighten cap on air fitting.
WARNING: System fluid under pressure and/
or at high temperatures can be very
hazardous. Before servicing, reduce system
pressure to zero or isolate the vessel from
B. INSTALLATION
The Bell & Gossett Series HFT pre-charged diaphragm
tank may be installed into a tee or any other suitable
tapping anywhere in the hot water heating system.
An ideal HFT tank installation is to screw it into the
bottom of a Bell & Gossett air separator (IAS, EAS or
EASB-JR) located on the supply line. This combination
offers both control of expanded water and continuous
automatic air removal from the system.
After installing Bell & Gossett HFT tanks on the system:
1. Fill system.
2. Vent air from system.
3. Bring system up to maximum operating temperature.
4. If an HFT tank is used with a volume smaller than
required to accommodate expanded water from a cold
start to maximum operating temperature, some
preliminary expanded water must be drawn from system
to bring operating pressure down to normal level. Drain
water from boiler until pressure reads at maximum range
(25 PSIG).
Generally, a smaller tank will cause a higher system
pressure than desired when system reaches operating
temperatures. This condition is normally referred to as a
Summer/Winter installation (boiler is always at
temperature). Tank should be tagged to denote this.
WARNING: This expansion tank, as all
expansion tanks, will eventually leak. Do not
install without adequate drainage provisions
where water flow will cause damage.
WARNING: CHLORINE & AGGRESSIVE
WATER HAZARD The water quality can
significantly influence the life of your
product. You should test for corrosive
elements, acidity, total solids, and other relevant
contaminants, including chlorine and treat your water
appropriately to insure satisfactory performance and
prevent premature failure. Failure to follow this
instruction may result in serious personal injury or
death and property damage.
SYSTEM VENTING AND PURGING
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 Bell & Gossett 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.
the system. Allow system to cool below 100°F and
above 35°F. Failure to follow this instruction may result
in serious personal injury and/or property damage.
WARNING: RUPTURE OR EXPLOSION
HAZARD Like most pressurized tanks, this
tank can over time corrode, weaken, and
burst or explode. Failure to follow this
instruction may result in serious personal injury or death
and property damage.
WARNING: A residential tank must be
installed vertically or horizontally. Do not
install on a dead end pipe or in an overhead
joist space.