Connections On The Dhw Side; Safety Valve - Viessmann Vitocell 300-B Installation Instructions Manual

Connections on the DHW side

■ For connections on the DHW side, observe
DIN 1988 and DIN 4753.
: SVGW regulations.
c
Connect all pipework with detachable fittings.
■
Seal any connections that are not required with red
■
brass caps.
■ Equip the DHW circulation pipe with a DHW circula-
tion pump, check valve and time switch.
Always install cylinder banks with connected DHW
■
circulation.
!
Please note
The internal indirect coil is installed with gas-
kets.
Temperatures > 150 °C at the connections will
■
damage the gaskets.
Ensure an adequate safety distance when sol-
dering and welding.
■ Realigning the connector will damage the gas-
kets.
D
F
E
G
C
A
Fig. 15
Expansion vessel
A
Drain
B
DHW circulation pipe
C
DHW
D
Spring-loaded check valve
E
DHW circulation pump
F
Visible discharge pipe outlet point (tundish)
G

Safety valve

H
Shut-off valve
K
Safety valve
The system must be equipped with a type-tested dia-
phragm safety valve as protection against overpres-
sure.
Permissible operating pressure: 10 bar (1 MPa).
The safety valve must have the following connection
diameter:
R (DN 20), max. heat input 150 kW.
¾
H
K M O
L N K
B
Permissible temperature:
Permissible operating pressure:
Test pressure:
P
K R K P
O S T
Flow regulating valve
L
Pressure gauge connection
M
Non-return valve
N
Drain
O
Cold water
P
Drinking water filter
R
Pressure reducer
S
Non-return valve/pipe separator
T
If the heat input of the DHW cylinder exceeds 150 kW,
select a sufficiently large safety valve for the heat input
(see DIN 4753-1, issue 3/88, section 6.3.1).
Install the safety valve in the cold water line. Ensure it
cannot be shut off from the DHW cylinder. There must
be no restrictions in the pipework between the safety
valve and the DHW cylinder.
95 °C
10 bar
(1 MPa)
16 bar
(1.6 MPa)
19