Fuel Supply; Hydraulic Connections - Riello RL 70/M Installation, Use And Maintenance Instructions

7
6
6
+ H
- H
(ft)
+ 13
+ 10
+ 6.6
+ 3.3
+ 1.6
0
- 1.6
- 3.3
- 6.6
- 10
- 13
(A)
(B)
5
A
1
4
5
3
7
B
L (ft)
Ø (inch)
3/8" 1/2" 5/8"
234 454 493
204 401 493
174 399 493
145 296 493
132 270 493
118 243 451
105 217 405
92 191 359
63 138 266
33 86 174
– 33 82
HYDRAULIC SYSTEM

FUEL SUPPLY

Double-pipe circuit (A)
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
Distance "P" must not exceed 33 ft in order to avoid sub-
jecting the pump's seal to excessive strain; distance "V"
must not exceed 13 ft in order to permit pump self-prim-
ing even when the tank is almost completely empty.
2
The tank lower than the burner B
Pump suction values higher than 13 "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 probable that the suction line fails to prime or
D737
stops priming.
The loop circuit
A loop circuit consists of a loop of piping exiting and
returning to the tank with an auxiliary pump that circu-
lates 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 dif-
ference are higher than the values listed in the Table.
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 = Return line
HYDRAULIC CONNECTIONS (B)
The pumps are equipped with a by-pass that connects
the return line and suction line. The pumps are installed
on the burner with the by-pass closed by screw
6)(A)p.13.
It is therefore necessary to connect both hoses to the
pump.
The pump seal will be dammaged immediately if it is
run with the return line closed and the by-pass
screw inserted.
Remove the plugs from the suction and return connec-
tions of the pump.
Insert the hose connections with the supplied seals into
the connections and screw them down.
D1224
Take care that the hoses are not stretched or twisted
during installation.
Install the hoses where they cannot be stepped on or
come into contact with hot surfaces of the boiler.
Now connect the other end of the hoses to the suction
and return lines.
8