1.80
1.60
1.40
1.20
1.00
0.80
0.60
0.40
0.20
0.00
0
2
4
6
8
10
12
14
16
155
70/110
70/110 Models
155 Model
Flow Through Heat Exchanger (GPM)
Pressure Dr
op (ft.
w
.c.)
Figure 45
Piping to diaphragm- (or bladder-) type
expansion tank
Part number 550-100-191/0917
42
®
g
as-fired water boiler —
70/110/155
Boiler Manual
EVG 70 or 110
EVG 155
Flow Rate
(GPM)
Head Loss
(ft. w.c.)
Flow Rate
(GPM)
Head Loss
(ft. w.c.)
3.0
0.11
7.0
0.39
5.0
0.30
9.0
0.65
6.5
0.51
11.0
0.97
8.0
0.77
13.0
1.35
10.0
1.20
14.5
1.68
Figure 46
Pressure drop through
EVG
heat exchanger (graph and table)
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 47 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 fi tting. Slope any horizontal piping a minimum of 1 inch
per 5 feet of horizontal pipe.
Always use a
tank fi tting
such as the B&G Tank-trol or Taco
Taco-trol (shown). The fi tting reduces gravity fl ow of water in
the piping to the tank, avoids air bubbling through the tank water,
and provides the proper fi 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. This 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. The air removed from the system will cause
water-logging of the expansion tank.
Closed-type expansion tank—Follow tank
manufacturer’s instructions for fi lling the tank.
Typical tank sizing provides for approximately
12 PSIG when the tank is fi lled to the normal
level and system water is cold. Note that boiler
relief valve is set for 30 PSIG. Operation
pressure of system, after temperature expansion
above cold fill pressure, should not exceed
24 PSIG to avoid weeping of relieve valve.
Direct Connect System Piping -
Single Boiler System
(continued)
Summary of Contents for Evergreen EVG 110
Page 71: ...Part number 550 100 191 0917 71 gas fired water boiler 70 110 155 Boiler Manual Notes...
Page 90: ...Part number 550 100 191 0917 90 gas fired water boiler 70 110 155 Boiler Manual Notes...
Page 116: ...Part number 550 100 191 0917 116 gas fired water boiler 70 110 155 Boiler Manual Notes...
