Riello 3739750 Installation, Use And Maintenance Instructions page 36

3.3 HYDRAULIC SYSTEMS
WARNING:
– Before starting the burner make sure that the return pipe-line is
not clogged. An excessive back pressure would cause the dam-
age of the pump seal.
– 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. 8).
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 be-
fore 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
required. 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;
2311
H
meters
0.5
Fig. 7
1
1.5
2
1 - Suction line
2 - Return line
3 - By-pass screw
4 - Gauge connection
5 - 2 nd stage pressure adjuster
Fig. 9
L = max. length of the suction line;
8
L meters
ø i ø i
8 mm 10 mm
10 20
20 40
40 80
60 100
Fig. 8
10 - 1st stage valve
11 - Auxiliary pressure test point
I. D. = internal diameter of the oil pipes.
4 GB
S7067
6 - Suction gauge connection
7 - 1 st stage pressure adjuster
8 - Pressure reducer piston
9 - 2 nd stage valve
L meters
H
ø i
meters
8 mm 10 mm
0 35
0.5 30
1 25
1.5 20
2 15
3 8
3.5 6
Fig. 10
ø i
100
100
100
90
70
30
20
D5744