Viessmann KOB Pyrot KRT Series 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
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 mixing valve
- PRV Pressure relief valve, pressure set to 30 or 60 psi
- TS2430 Thermal run-off safety 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 Pyrot 150 to Pyrot 300 have one safety heat
exchanger loop and require one thermal run-off safety
valve. The Pyrot-400 and Pyrot-540, have two safety
heat exchanger loops and require one thermal run-off
safety 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 run-off safety valve
Boiler Thermal run-off
Model safety valve
KRT- TS-2430
(Quantity)
150 1
220 1
300 1
400 1
540 1
Pressure relief valve
Boiler Pressure relief
Model valve Conbraco
KRT- 30 psi or 60 psi
150 c in.
1 in.
c in.
220 1 in.
300
1a in.
400
1a in. 1a in.
540
1b in. 1a 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 GPM
915 4
1230 5.4
1500 6.6
1880 8.3
2226 10
Pressure relief
1
valve drain pipe
2
PDP
30 psi or 60 psi
1a in. 1 in.
1a in. 1 in.
1 in. 1b in. 1a in.
1b in. 1b in.
2 in. 1b in.
(continued)
Equipment to be supplied by the installing heating
contractor:
- PDPPressure 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 Drain pipe
2
line SDP
WSL
R c in.
R 1 in.
R c in.
R 1 in.
R c in. R 1 in.
R c in.
R 1 in.
R c in.
R 1 in.
Pyrot Technical Data