Viessmann Vitoflex 300-RF Technical Data Manual page 26

Mechanical
Piping and Installation of Safety Devices
Note: To reliably prevent boiler corrosion caused
by condensation of flue gases, the boiler return
temperature must not under any circumstances
be below 150°F (65°C).
A Viessmann sized boiler pump with a boiler
3-way mixing valve are provided according to the
tables below. The boiler circuit should be designed
that the temperature difference between the supply
and the return temperature is equal to or less than
∆t 27°F (15°C).
The expansion tank has to be connected to the
boiler without any shut-offs.
Safety equipment included in the scope of supply provided
by Viessmann:
- M 20 Boiler pump
- Y 20 Boiler 3-way mixing valve
- PRV Pressure relief valve, pressure set to 30 or 60 psi
- TS2430 Thermal safety flush valve R ¾ in., approved
component; special-purpose, designed for opening at a
temperature of 122°-248°F (50°-120°C), (safety heat
exchanger loop built into the boiler).
The Vitoflex 300-RF 150 to Vitoflex 300-RF 300 have
one safety heat exchanger loop and require one thermal
safety flush valve. The Vitoflex 300-RF 400 and
Vitoflex 300-RF 540, have two safety heat exchanger
loops and require one thermal safety flush valve.
- LWCO Low water cut-off
- PG Pressure gauge
- TG Temperature gauge (thermometer)
- SHE Safety heat exchanger, water volume 1.1 USG
(4.2L) per loop, NPTM b in.
Design recommendation:
Thermal safety flush valve
Boiler Model Thermal safety
flush valve
TS-2430
(Quantity)
RF 150
RF 220
RF 300
RF 400
RF 540
Pressure relief valve
Boiler Model Pressure
relief valve
Conbraco
30 psi
RF 150 1 in.
RF 220 1 in.
RF 300 1a in.
RF 400
1a in.
RF 540
1b in.
1 Threaded connection for supply line
2 Length of the drain pipe up to 13 ft. (4.0 m)
26
Water through-put
required at
36 psi (2.5 bar)
L/h
1 915
1 1230
1 1500
1 1880
1 2226
Pressure
relief valve
1 Conbraco 1
60 psi
c in.
c in.
1 in.
1 in.
1a in.
(continued)
Equipment to be supplied by the installing heating
contractor:
- PDP Pressure relief valve drain pipe
- DCW Cold water inlet, min. 36 psi (2.5 bar), max.
51 psi (3.5 bar)
- AV Air separator / vent
- ExP Expansion tank closed;
- for safety heat exchanger required (size according
to volume of safety heat exchanger loops and volume
of piping)
- for heating system (optional)
- WSL Water supply line for safety heat exchanger
- SDP Safety heat exchanger drain pipe
- SRL System return line to the boiler from the system
- SSL System supply line from the boiler to the system
- BPL Bypass line
- BR Boiler return
- BS Boiler supply
Supply line
WSL
GPM
4
R c in.
5.4
R c in.
6.6
R c in.
8.3 R c in.
10
R c in.
Pressure Pressure
relief valve relief valve
drain pipe PDP 2 drain pipe PDP
30 psi 60 psi
1a in.
1a in.
1b in. 1a in.
1b in. 1a in.
2 in.
1b in.
Vitoflex 300-RF Technical Data
Drain pipe
SDP 2
R 1 in.
R 1 in.
R 1 in.
R 1 in.
R 1 in.
2
1 in.
1 in.