Freestyle 2 Series - Closed-Type Expansion Tank

Part number 550-142-950/0122
41
FreeStyle
®
series 2 wall mount gas-fired water boiler – boiler manual
Figure 53 Piping to closed-type expansion tank
18 Primary/Secondary System Piping (continued)
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53 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 outlet to the
tank tting. Slope any horizontal piping a minimum of 1 inch
per 5 feet of horizontal pipe.
Always use a tank tting such as the B&G Tank-trol or Taco
Taco-trol (shown). e tting reduces gravity ow of water in
the piping to the tank, avoids air bubbling through the tank
water, and provides the proper ll 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. is 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. e air removed from the system
will cause water-logging of the expansion tank.
Closed-type expansion tank—Follow tank
manufacturer’s instructions for lling the tank.
Typical tank sizing provides for approximately 12
PSIG when the tank is lled to the normal level
and system water is cold. Note that boiler relief
valve is set for 30 PSIG. Operation pressure of
system, aer temperature expansion above cold
ll pressure, should not exceed 24 PSIG to avoid
weeping of relieve valve.
Graph 1 Pressure drop through FreeStyle
®
80/120/155 heat exchanger
Taco 007
Taco 0014
Grundfos UPS 15-58
(High)
Taco 0015 (High)
B&G NRF 25 (High)
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
0 1 2 3 4 5 6 7 8 9 10 11 12
Total Head - feet water
Flow - gpm
1
1 = Boiler Pressure Drop with 3/4'' near boiler piping (80KBTU and120 KBTU)
2 = Boiler Pressure Drop with 1'' near boiler piping (80KBTU and120 KBTU)
3 = Boiler Pressure Drop with 1 '' near boiler piping (155 KBTU)
4 = Boiler Pressure Drop with 1 1/4'' near boiler piping (155 KBTU)
2
3
4
Taco 0011