19
6423
GB
Hydraulic system
6.1.3
Single-pipe circuit
In order to obtain single-pipe working it is necessary to unscrew
the return hose, remove the by-pass screw 6)(Fig. 29) and then
screw the plug 7)(Fig. 29).
The distance “P” must not exceed 10 meters in order to avoid
subjecting the pump's seal to excessive strain; the distance "V"
must not exceed 4 meters.
For the priming pump loosen the screw 3)(Fig. 20) in order to
bleed off the air contained in the suction line and wait until the fuel
flows out.
Key (Fig. 18)
H Pump/Foot valve height difference
L Piping length
ø Inside pipe diameter
1
Burner
2
Pump
3
Filter
4
Manual on/off valve
5
Suction line
6
Foot valve
7
Rapid closing manual valve remote controlled (only Italy)
8
On/off solenoid valve (only Italy)
11 Tank filter
Tab. H
6.2
Hydraulic connections
The pumps are equipped with a by-pass that connects return line
with suction line. The pumps are installed on the burner with the
by-pass closed by screw 6)(Fig. 29 on page 26).
It is therefore necessary to connect both hoses to the pump.
The pump will break down immediately if it is run with the return
line closed and the by-pass screw inserted.
Remove the plugs from the suction and return connections of the
pump.
Insert the hose connections with the supplied seals into the con-
nections and screw them down.
Take care that the hoses are not stretched or twisted during in-
stallation.
Route the hoses through the holes in the plate, preferably
using those on the right side (Fig. 19);
unscrew the screws 1), now divide the insert piece into its
two parts 2) and 3);
remove the thin diaphragm blocking the two passages 4).
Install the hoses where they cannot be stepped on or come
into contact with hot surfaces of the boiler.
Now connect the other end of the hoses to the supplied nip-
ples, using two wrenches, one to hold the nipple steady
while using the other one to turn the rotary union on the
hose.
+/- H
L (meters)
(meters)
ø 8 mm
ø 10 mm
ø 12 mm
+ 4.0
51
100
100
+ 3.0
45
100
100
+ 2.0
39
95
100
+ 1.0
33
80
100
+ 0.5
29
72
100
5
7
6
5
3
4
A
2
1
P
+H
8
10
c
m
V
11
Fig. 18
D11077
Fig. 19
1
2 3
4
D3279
