Hydraulic System - Riello RL 25 BLU TC Installation, Use And Maintenance Instructions

7
6
6
20156631
Key
H = Pump/Foot valve height difference
L = Piping length
values calculated for light oil:
• viscosity = 6 cSt / 20 °C
• density = 0,84 kg/dm
• temperature = 0 °C
• max. altitude = 200 m (a.s.l.)
Ø = Inside pipe diameter
1 = Burner
2 = Pump
3 = Filter
4 = Manual on/off valve
5 = Suction line
6 = Foot valve
7 = Return line
5
4
5
7
+H
-H
m
8
+4 52
3
+3 46
+2 39
+1 33
+0,5 30
0 27
-0,5 24
-1 21
-2 15
-3 8
-4 -
A
1
2
3
B
L m
Ø mm
10 12
134 160
119 160
104 160
89 160
80 160
73 160
66 144
58 128
43 96
28 65
12 33
10

HYDRAULIC SYSTEM

FUEL SUPPLY
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.
There are three types of fuel hydraulic circuits:
• Double-pipe circuits (the most common)
• Single-pipe circuits
• Loop circuits.
According to the burner/tank layout, either of two
fuel supply systems can be used:
• siphon-type (with the tank higher than the
burner);
• suction-type (with the tank lower than the
burner).
DOUBLE-PIPE SIPHON-TYPE SYSTEMS (A)
The distance P must not exceed 10 meters in or-
der to avoid subjecting the pump's seal to exces-
sive strain; the distance V must not exceed 4
meters in order to permit pump self-priming even
when the tank is almost completely empty.
DOUBLE-PIPE SUCTION-TYPE SYSTEMS (B)
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 improbable that
the suction line fails to prime or stops priming.
USEFUL SUGGESTIONS FOR BOTH SYS-
TEMS (A) AND (B)
- Use copper pipes whenever possible.
- Any curves used in the system should be
made with the widest possible radius.
- Use biconic connectors at both ends of the
pipe.
- Whenever the burner is installed in areas with
extremely cold winter climates (temperatures
lower than - 10°C), we recommend insulating
both the tank and the piping. Avoid the small-
est of the three pipe diameters provided in the
Table and lay the piping along the most shel-
tered route possible. The paraffin in the fuel
begins to solidify below 0°C, and the filters and
nozzle begin to clog accordingly.
- Install a filter on the suction lines with a trans-
parent plastic bowl if possible in order to per-
mit the regular flow of fuel and quick checking
of the state of the filter.
- The return pipe does not require an on/off
valve, but if the user desires to insert one, a le-
ver-type valve should be selected which clear-
ly indicates when the valve is open or closed
(if the burner starts with the return pipe closed,
the sealing organ located on the pump shaft
will break).
- Copper pipes must be installed to a position
with respect to the burner that allows the latter
to be fully retracted on its slide bars without
stretching or twisting the flexible hoses.
- 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 re-
turn line. Install a T union on the vacuum me-
ter attachment. On one branch of this T install
a pressure gauge and on the other branch in-
ject air at a pressure of 1 bar. After the air in-
jection, the gauge must remain at a constant
pressure.