3126
5
3.3 HYDRAULIC SYSTEMS
The pump is designed to allow working with two pipes.
In order to obtain one pipe working it is necessary to unscrew the return
plug (2) (fig. 4), remove the by-pass screw (3) and then screw again the
plug (2).
In the two pipes systems, before starting the burner make sure that
the return pipe-line is not clogged. An excessive back pressure would
cause the damage of the pump seal.
A metal bowl filter with replaceable micronic filter must be fitted in the
oil supply pipe.
Check periodically the flexible pipes conditions.
PRIMING PUMP
On the system in fig. 5
it is sufficient to loosen the suction gauge
connection (6) (fig. 4) and wait until oil flows out.
The suction plug (1) is made of plastic. Once removed,
it must not be used again.
In single-pipe installations, the plug in the return line (2)
must be totally in steel.
WARNING
7
Fig. 4
6
5
4
3
2
1
8
D9630
H
ma
x.
4
m
mi
n.
0.
1 m
D5741
Fig. 5
H
meters
L meters
I.D.
8 mm
I.D.
10 mm
0.5
1
1.5
2
10
20
40
60
20
40
80
100
On the systems in fig. 6 and 7
start the burner and wait for the priming.
Should lock-out occur prior to the arrival of the fuel, await at least 20 seconds before repeating the operation.
In the vacuum systems (fig. 7) the return line should terminate within the oil tank at the same level as the suc-
tion line. In this case a non-return valve is not required.
Should however the return line arrive over the fuel level, a non-return valve is required. This solution how-
ever is less safe than previous one, due to the possibility of leakage of the valve.
The pump suction should not exceed a maximum of 0.4 bar (30 cm Hg). Beyond this limit gas is re-
leased from the oil.
Oil pipes must be completely tight.
WARNING
1 Suction line
2 Return line
3 By-pass screw
4 Gauge connection
5 Pressure adjuster
6 Suction gauge connection
7 Valve
8 Auxiliary pressure test point
D5740
m
ax.
4 m
H
H
max. 4 m
H
H
D1842
Fig. 6
Fig. 7
H
meters
L meters
I.D.
8 mm
I.D.
10 mm
0
0.5
1
1.5
2
3
3.5
35
30
25
20
15
8
6
100
100
100
90
70
30
20
H
= difference of level;
L
= max. length of the suction line;
I.D.
= internal diameter of the oil pipes
