14
FUTERA III INSTALLATION AND OPERATION INSTRUCTIONS
Table 7 - Temperature Rise Table
∆
T = 20
°
F
∆
T = 11.1
°
C
Model
Flow Rate
Pres. Drop
Flow Rate
Pres. Drop
Number
GPM
Ft
L/s
kPa
500
42.5
0.53
2.7
1.5
750
63.8
1.57
4.0
4.6
1000
85.0
3.44
5.4
10.1
1250
106.3
2.11
6.7
6.2
1500
127.5
3.57
8.0
10.5
∆
T = 25
°
F
∆
T = 13.9
°
C
Model
Flow Rate
Pres. Drop
Flow Rate
Pres. Drop
Number
GPM
Ft
L/s
kPa
500
34.0
0.35
2.1
1.0
750
51.0
1.04
3.2
3.1
1000
68.0
2.27
4.3
6.7
1250
85.0
1.40
5.4
4.1
1500
102.0
2.36
6.4
7.0
1750
119.0
3.67
7.5
10.8
2000
136.0
5.39
8.6
15.9
∆
T = 30
°
F
∆
T = 16.7
°
C
Model
Flow Rate
Pres. Drop
Flow Rate
Pres. Drop
Number
GPM
Ft
L/s
kPa
750
42.5
0.74
2.7
2.2
1000
56.7
1.62
3.6
4.8
1250
70.8
1.00
4.5
2.9
1500
85.0
1.68
5.4
5.0
1750
99.2
2.62
6.3
7.7
2000
113.3
3.84
7.2
11.3
∆
T = 35
°
F
∆
T = 19.4
°
C
Model
Flow Rate
Pres. Drop
Flow Rate
Pres. Drop
Number
GPM
Ft
L/s
kPa
750
36.4
0.56
2.3
1.6
1000
48.6
1.22
3.1
3.6
1250
60.7
0.75
3.8
2.2
1500
72.9
1.27
4.6
3.7
1750
85.0
1.97
5.4
5.8
2000
97.1
2.89
6.1
8.5
Low Water Cutoff
If a boiler is installed above any radiation elements it must
be fitted with a low water cutoff device.
Refer to the wiring diagram supplied with the boiler/water
heater for proper wiring connections.
Expansion Tank & Air Separator
An expansion tank or other means to control thermal
expansion must be installed in the heating system. An
expansion tank must be installed close to the boiler on the
suction side of the pump. An air scoop and automatic air
vent must also be installed to eliminate air trapped in the
system.
Primary/Secondary Piping
Boilers connected to heating systems using zone valves,
zone pumps, or systems that have excessive flow rates or
return water temperatures less than
125˚F
,
52˚C must be
isolated from these systems to protect the boiler.
Variable Water Flows
Figure 9 shows a typical primary/secondary piping system.
A dedicated pump is used to maintain a constant water flow
through the boiler. This secondary pump is sized to
overcome the head loss of the boiler and secondary piping
system while supplying the flow rate required to maintain
the desired temperature rise across the boiler. The primary
pump is sized to provide the required flow to the heating
system. The secondary piping connections to the primary
system piping must not be more than
12 in
,
305 mm apart
to ensure zero pressure drop in the primary system, see
Figure 9.
Low Return Water Temperatures
To prevent the problems associated with condensation of
the products of combustion due to low return water
temperatures a primary/secondary piping system with a
bypass and bypass valve must be installed, see Figure 10.
The bypass and bypass valve must be sized the same
as the secondary piping. A balancing valve must also be
installed in the supply side of the secondary piping
downstream of the bypass. The balancing valve should
be adjusted to divert some of the heated discharge water
into the return water until the required inlet water
temperature is achieved. The primary and secondary
pumps should be sized to provide the required flow through
each system. The secondary piping connections to
the primary system piping must not be more than
12 in
,
305 mm apart to ensure zero pressure drop in the primary
system, see Figure 10.
Multiple Boiler Systems
Systems using multiple boilers can also be installed using
a primary/secondary manifold system, Figure 11.
Piping For Use With Cooling Units
The boiler, when used in connection with a refrigeration
system, must be installed so the chilled medium is piped
in parallel with the boiler. Appropriate valves must be used
to prevent the chilled water from entering the boiler.
When a boiler is connected to a heating coil that may be
exposed to refrigerated air from an air handling device, the
piping system must be equipped with flow-control valves
or some other automatic means of preventing gravity
circulation of the boiler water during the cooling cycle.
