Riello Burners RG4S Installation, Use And Maintenance Instructions page 24

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 pin (2), remove the by-pass screw (3) and then screw again
the pin (2), (see fig. 8).
It is necessary to install a filter on the fuel supply line.
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
D5745
PRIMING PUMP:
On the system in fig. 7 it is sufficient to loosen the suction gauge
connection (6, fig. 8) and wait until oil flows out.
On the systems in fig. 9 and 10 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. 10) 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.
H = difference of level;
2310
H
meters
0.5
Fig. 7
1
1.5
2
Fig. 9
L = max. length of the suction line;
D5527
L meters
I. D. I. D.
8 mm 10 mm
10 20
20 40
40 80
60 100
I. D. = internal diameter of the oil pipes.
4 GB
1
Fig. 8
1 - Suction line
2 - Return line
3 - By-pass screw
4 - Gauge connection
5 - Pressure adjuster
6 - Suction gauge connection
7 - Valve
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. 10
7
6
5
4
3
2
I. D.
10 mm
100
100
100
90
70
30
20
D5744