Table of Contents
Advertisement
–
The opening of the burner or the boiler door must not twist the
flexible hoses that connect the copper pipes to the pump.
–
If more than one burner is operating in the same room, each
one must be equipped with its own suction pipe; the return
pipe may be shared by all, providing it is sufficiently sized.
–
The suction line must be perfectly airtight. In order to check
the seal, close the pump's return line. Install a union T on the
vacuum meter attachment. On one branch of this T install a
pressure gauge and on the other branch inject air at a pres-
sure of 1 bar. After the air injection, the gauge must remain at
a constant pressure.
5.11.3 Single-pipe systems
There are two solutions possible:
–
Pump external by-pass A)(Fig. 19) (recommended)
Connect the two flexible hoses to an automatic degassing
unit. The pump by-pass screw must not be removed.
–
Pump internal by-pass B)(Fig. 19)
The pumps are equipped with a screw 6)(Fig. 26 on
page 24), which is accessible through the return line connec-
tor, which when removed opens the return pipe to the suction
line.
The pump return line connector must be plugged.
This solution is possible only with low pump depression values
(max. 0.2 bar) and perfectly-sealed piping.
5.11.4 Loop circuit
This is composed by piping that leaves from the tank and returns
to the same 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. K.
Contact our Engineering Department for further information re-
garding single-pipe systems and the loop circuit.
Altitude
Altitude has a determined effect on pump suction power.
At altitudes of more than 200 meters above sea level, the level
difference, in metres, between the pump and the foot valve must
be corrected by the factor "F", see Tab. E on page 10, in order to
obtain the equivalent height difference with which to determine
the maximum piping length, i.e.:
–
if a suction-type system is involved:
(equivalent) He = (real) H + F
–
if a siphon-type system is involved:
(equivalent) He = (real) H - F
where: F = (real altitude) (m - 200) / 1000
20098582
Installation
D349
A
m
200
300
F
0
0.1
Key (Tab. K)
m = Altitude in m a.s.l.
F = correction factor
Example:
Suction type system
Piping diameter
Altitude
F
- H
Piping length
18
GB
B
600
900
1200 1500 1800 2100
0.4
0.7
1.0
1.3
- H = 2 m
Ø = 10 mm
m
200
0
m
2
m
27
Fig. 19
1.6
1.9
Tab. K
1200
1
2 + 1 = 3
16
Tab. L
Advertisement
Table of Contents
