Gas Oil Supply; 5.10.1 Double-Pipe Circuit; 5.10.2 The Loop Circuit - Riello RL 190/M Installation, Use And Maintenance Instructions

5.10

Gas oil supply

Where gas oil containing bio diesel is in use, it is
recommended to avoid over oxygenation of the
blended fuels.
Where at all possible avoid the use of two pipe
WARNING
systems where the circulated fuel is returned to
the tank.
If this cannot be avoided make sure that the return
pipe is normally below the surface of the fuel level
within the storage tank.
In case of use with gas oil containing up to 10%
Bio blend, it will be essential to use flexible oil
lines suitable for bio fuel use.
WARNING
Please contact Riello for further information.
It is strongly recommended a periodic check of
the pump pressure operation (annually or better
every six months, if the burner operation is contin-
uous).
DANGER
You are advised to use additional filters on the fuel
supply line.
Riello recommends a good quality fuel filter at the
tank (Fig. 17 - Fig. 18) and a secondary filter
CAUTION
(100  for gas oil and 15  for kerosene) are used
to protect the burner pump and nozzle from con-
tamination.
In case of Biodiesel use, pay attention to install
Biocompatible filters.

5.10.1 Double-pipe circuit

The burner is equipped with a self-priming pump which is capable
of feeding itself within the limits listed in the Tab. F.
The tank higher than the burner A (Fig. 17)
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 in order to permit pump self-priming
even when the tank is almost completely empty.
The tank lower than the burner B (Fig. 17)
Pump depression values higher than 0.45 bar (35 cm Hg) must
not be exceeded because at higher levels gas is released from
the fuel, the pump starts making noise and its working life-span
decreases.
It is good practice to ensure that the return and suction lines enter
the burner from the same height; in this way it will be more im-
probable that the suction line fails to prime or stops priming.

5.10.2 The loop circuit

A loop circuit consists of a loop of piping departing from and re-
turning to the tank with an auxiliary pump that circulates the fuel
under pressure.
A branch connection from the loop goes to feed the burner.
This circuit is extremely useful whenever the burner pump does
not succeed in self-priming because the tank distance and/or
height difference are higher than the values listed in the Tab. F.
Installation
11 7
10
6
11
7
6
Key (Fig. 17)
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)
9 Return line
10 Check valve (only Italy)
11 Tank filter
+/- H
(meters)
+ 4.0
+ 3.0
+ 2.0
+ 1.5
+ 1.0
+ 0.5
0
- 0.5
- 1.0
- 1,5
- 2.0
- 3.0
- 4.0
17
GB
A
5
9
8
4
5
9
B
D11078
L (meters)
Ø 16 (mm)
60
50
40
35
30
25
20
18
15
13
10
5
-
1
2
3
Fig. 17
Ø 18 (mm)
80
70
60
55
50
45
40
35
30
25
20
10
6
Tab. F
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