Riello RDB1R GRANT MILTON 20 kW Installation, Use And Maintenance Instructions page 14

On the systems in Fig. 13 and Fig. 14 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 order to purging air from oil lines and filters re-
peat for maximum 5 times the complete operation
programme, to protect the pump.
The pump suction should not exceed a maximum
WARNING
of 0.4 bar (30 cm Hg). Beyond this limit gas is re-
leased from the oil. Oil pipes must be completely
tight.
D1842
H
metres
0
0.5
1
1.5
2
3
3.5
H difference of level
L maximum length of the suction line
Ø internal diameter of the oil pipes
20166849
60 µm
60 µm
L metres
Ø (8 mm) Ø (10 mm)
35 100
30 100
25 100
20 90
15 70
8 30
6 20
Installation
In the vacuum systems (Fig. 14) 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 re-
turn 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.
D5740
NOTE:
In case of digital applications the priming pump is possible
not only with the previous procedure but also with a specific
function implemented into the digital control box (see 4.7.9,
page 10). In this case the priming pump time could be longer.
Fig. 13
Tab. E
12 GB
60 µm
Fig. 14