15
Air-Separation/Expansion Tank
All heaters should be equipped with a properly sized
expansion tank and air separator fitting as shown in
Fig. 12 .
Fig. 12: Air-Separation/Expansion Tank
System
Return Temp
Supply Temp
1
Supply Temp
1
Supply Temp
1
(°F)
(°F)
<80' equiv. 80-200' equiv.
(°F)
<80' equiv. 80-200' equiv.
(°F)
<80' equiv. 80-200' equiv.
60
138
2"NPT
2 1/2"NPT
147
2"NPT
2 1/2"NPT
154
2"NPT
2 1/2"NPT
80
138
2"NPT
2 1/2"NPT
147
2"NPT
2 1/2"NPT
154
2 1/2"NPT
3"NPT
100
138
2 1/2"NPT
3"NPT
147
2 1/2"NPT
3"NPT
154
2 1/2"NPT
3"NPT
120
145
2 1/2"NPT
3"NPT
158
2 1/2"NPT
3"NPT
170
2 1/2"NPT
3"NPT
140
165
2 1/2"NPT
3"NPT
178
2 1/2"NPT
3"NPT
190
2 1/2"NPT
3"NPT
160
185
2 1/2"NPT
3"NPT
198
2 1/2"NPT
3"NPT
210
2 1/2"NPT
3"NPT
1
-Approximate high fire heater outlet temperature based on the standard heater pump and the recommended connecting pipe size.
Model 1005
Minimum Pipe Size
2
Model 1505
Minimum Pipe Size
2
Model 2005
Minimum Pipe Size
2
2
-Minimum pipe size based on total equivalent feet of supply and return piping between the system loop and heater.
Table F: Boiler Temperatures and Minimum Pipe Size at Varying Return Temperatures
Fitting Type
Equivalent Length (ft)
2-1/2” NPT
3” NPT
90° Elbow (Std.)
8.5
9.4
90° Elbow (Long rad.)
3.5
3.6
45° Elbow
3.0
3.4
Gate Valve (Full open)
1.6
1.6
Swing Check Valve
22
25
