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22
Installation
6.11.5 Priming pump
In the systems A and B of Fig. 21 start the burner and wait for the
priming.
Should lockout occur prior to the arrival of the fuel, await at least
20 seconds before repeating the operation.
The pump vacuum should not exceed a maximum of 0.4 bar (30
cm Hg).
Beyond this limit gas is released from the oil.
In vacuum systems B (Fig. 21) we recommend bringing the return
line to the same height 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.
H = Difference of level
L = Maximum suction line length
Ø = Inner diameter of the pipe
Tab. H
The pipes must all be perfectly sealed.
H L metres
metres Ø (8 mm) Ø (10 mm)
0 35 100
0.5 30 100
1 25 100
1.5 20 90
2 15 70
3 8 30
3.5 6 20