3.3 HYDRAULIC SYSTEMS
WARNING:
■ 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), remove the by-pass screw
(3) and then screw again the plug (2). (See fig. 5).
■ 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.
SYSTEM NOT PERMITTED
IN GERMANY
Fig. 6
PRIMING PUMP:
On the system in fig. 6 it is sufficient to loosen the suction gauge
connection (5, fig. 5) and wait until oil flows out.
On the systems in fig. 7 and 8 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.
The pump suction should not exceed a maximum of 0.4 bar (30 cm Hg).
Beyond this limit gas is released from the oil. Oil pipes must be completely tight.
In the vacuum systems (fig. 8) the return line should terminate within the oil tank
at the same level as the suction line. In this case a non-return valve is not re-
quired. Should however the return line arrive over the fuel level, a non-return
valve is required.
This solution however is less safe than previous one, due to the possibility of
leakage of the valve.
It is necessary to install a filter on the fuel supply line.
H = difference of level;
1913
meters
D5713
Fig. 7
L = max. length of the suction line;
8
1
2
3
L meters
H
I. D.
I. D.
8 mm
10 mm
0.5
10
20
1
20
40
1.5
40
80
2
60
100
I. D. = internal diameter of the oil pipes.
4
GB
D5026
4
5
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 gauge
L meters
H
I. D.
meters
8 mm
0
35
0.5
30
1
25
1.5
20
2
15
3
8
3.5
6
Fig. 8
Fig. 5
6
7
I. D.
10 mm
100
100
100
90
70
30
20
D5714