Viessmann Vitogas 050 Rs Series Installation & Service Manual page 9

Gas
pipe
Vitotronic control
Lubricated 3.6 85
2.0 70 flF
0.4 55
plug valve
Mount relief
valve, air vent
and pressure
gauge to
tapping on left
hand side
Drip leg
with cap
Mount drain valve
to lower tapping
Fig. 11
Standard Vitogas 50, RS boiler piping connections
RS boiler with right hand water piping, left hand gas piping
(Boiler shown with access panel removed)
4.2 Pump selection and pump aquastat
Fig. 12 shows the head loss through the boiler at
various flow rates for the Vitogas 50 boilers.
The minimum return water temperature is 120°F
(48.8°C). The maximum temperature rise between
return and supply is 68°F (37.7°C).
7.0 28
6.5 26
6.0 24
5.5 22
5.0 20
4.5 18
4.0 16
3.5 14
3.0 12
2.5 10
2.0 8
1.5 6
1.0 4
0.5 2
0 0
0
0
Fig. 12
Head loss through boiler
Flow direction must
be as shown
Return Supply
Sensing well
Power
for aquastat
120V
capillaries
60 Hz
Low water
2˝ 2˝
cut-off
75
90
flC
probe or
flC
float type
Min. 2˝ above
2˝
supply pipe
centerline
Pilot burner
mounting side
10 20 30
38 76 114
4.3 Initial system fill
Treatment for boiler feed water should be considered in
areas of known problems, such as high mineral content
and hardness. In areas where freezing might occur, an
antifreeze may be added to the system water to protect
the system. Please adhere to the specifications given
by the antifreeze manufacturer. Never use silicate
based automotive antifreeze.
Please observe that an antifreeze/water mixture may
require a backflow preventer within the automatic water
feed and influence components such as diaphragm
expansion tanks, radiation, etc. A 40% antifreeze
content will give freeze-up protection to approximately
-10°F (-23.3°C). Do not use antifreeze other than
specifically made for hot water heating systems. System
also may contain components which might be
negatively affected by antifreeze. Check total system
frequently when filled with antifreeze.
A pressure reducing valve (or "fill" valve) is required to
reduce the incoming water pressure. The total of the fill
pressure, pump head, and any small pressure rise from
thermal expansion of the water must be less than the
boiler pressure relief valve setting. An expansion tank
must be connected to the system close to the suction
side of the circulating pump to prevent pressure
increase resulting from thermal expansion of the system
water.
40 50 60 70
152 190 228 266
FLOW
80 90 100 USG/min
304 342 380 ltr./min
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