15
5790 733 - 07
Vitocrossal 300 CA3 Series 2.5 to 6.0 Installation/Service
Boiler Connections
(continued)
*1
Counter flanges, gaskets and hardware (field supplied)
*2
Alternate pressure relief valves are available depending
on operating pressure requirements. Contact your local
Viessmann sales representative for details.
Installation
Legend
1
Boiler return: (ANSI 4 in. for models 2.5, 3.0, 3.5,
4.0 and 5.0 and ANSI 6 in. for model 6.0)
*1
2
Boiler supply: (ANSI 4 in. for models 2.5, 3.0, 3.5,
4.0 and 5.0 and ANSI 6 in. for model 6.0)
*1
3
Safety header: (Pressure relief valve, low water cutoff,
automatic air vent and temperature/pressure gauge)
A
Hex bushing
b
in. x
e
in.
B
Air vent with shut-off base
C
Plug
b
in.
D
Reducer 2 in. to 1 in. for models 2.5 and 3.0,
2 in. to 1
a
in. for models 3.5 and 4.0,
2 in. to 1
b
in. for models 5.0 and 6.0
E
Nipple 1 in. for models 2.5 and 3.0
1
a
in. for models 3.5 and 4.0
1
b
in. for models 5.0 and 6.0
F
Pressure relief valve, 75 psi
*2
G
Low water cutoff
H
Temperature/pressure gauge
4
Drains:
I
Nipple 1
b
in. x 10
in.
J
Reducer 1
b
in. x
c
in.
K
Sediment faucet
c
in.
5
Gas line fittings:
L
Gas gas shut-off valve,
2
b
in. for models 2.5, 3.0, 3.5
and 4.0, 3 in. for models 5.0 and 6.0
