Safety Devices - Viessmann Vitoflex 300-RF Technical Data Manual

Mechanical

Safety Devices

Boiler system with return valve
To reliably prevent boiler corrosion through condensation
of the flue gases, the boiler return temperature must never
be below 149°F (65°C).
The step less control of the Vitoflex 300-RF rotating
combustion chamber requires a constant flow through the
boiler of the water to be heated. The boiler circuit, the
boiler pump and boiler 3-way mixing valve must therefore
be installed according to section piping and installation of
safety devices.
The boiler circuit should be designed that the temperature
difference between the boiler supply and the boiler return
temperature is equal to or less than 27°F (15°C).
The activation of the boiler pump and boiler 3-way mixing
valve is integrated in the custom control panel.
The safety equipment for the heating installation must be
installed by the heating contractor authorized to do so.
Legend
A Nipple, c in. x 1b in.
B Reducing coupling, c in. x b in.
C Boiler water temperature gauge
D Bushing c in. x a in.
E Nipple a in. x 2b in.
F Ball valve a in.
G Pressure gauge
H Reducing coupling
I Reducing bushing
J Nipple
K Pressure relief valve, 30 psi or 60 psi
C
B
A
R
24
K
G
J
I
F
H
E
D
P
Q
Fire extinguishing water tank
The self-activating extinguishing device must be installed
next to the boiler feed system. Refer to section fire
extinguishing systems for the assembly.
The fire suppression is performed by means of an
extinguishing valve, which is not dependent on an electric
current. A float-type switch monitors the water level and
should be electrically connected (see field wiring diagram).
L Safety heat exchanger connections, NPTM b in.
M Sensor well - fixed high limit
N 3 in. or 4 in. Boiler supply flange
O Supply sensor well (sensor supplied)
P Return sensor well (sensor supplied)
Q 3 in. or 4 in. Boiler return flange
R Sensor well for thermal safety flush valve (Rb in.)
(sensor supplied)
M
L
L
See section piping and installation of safety devices
1
3 in. boiler flange for Vitoflex 300-RF 150-300, 4 in.
2
boiler flange for Vitoflex 300-RF 400-540
Note: All fittings shown and sensors indicated are factory
supplied. The size and quantity are matched to the
specific boiler model.
Vitoflex 300-RF Technical Data
2
2
N
O
1