Hydraulic System; Fuel Supply - Baxi 3475061 Installation, Use And Maintenance Instructions

6

Hydraulic system

6.1

Fuel supply

Double-pipe circuit (Fig. 19)
The burner is equipped with a self-priming pump which is capable
of feeding itself within the limits listed in the table at the side.
The tank higher than the burner A
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
Pump depression of 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 less proba-
ble that the suction line fails to prime or stops priming.
Hydraulic system
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 dis-
tance and/or height difference are higher than the values listed in
the table.
+ H
- H
(m)
+ 4.0
+ 3.0
+ 2.0
D701
+ 1.0
+ 0.5
0
- 0.5
- 1.0
- 2.0
Fig. 19 - 3.0
- 4.0
Key
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)
17 GB
L (m)
TECNO 70-L TECNO 100-L - 130 L
Ø (mm)
10 12 14 12
51 112 150 71
45 99 150 62
39 86 150 53
32 73 144 44
29 66 132 40
26 60 120 36
23 54 108 32
20 47 96 28
13 34 71 19
7 21 46 10
- 8 21
Ø (mm)
14 16
138 150
122 150
106 150
90 150
82 150
74 137
66 123
58 109
42 81
26 53
- 10 25
Tab. D
6088