Nu-Way PO160, Installation & Maintenance Manual

Page: 19 / 56

PO Series Technical Specification Page C.4
- motorised spill control valve
- non-return valve
Pumping Set For Class D Fuel
The pump unit is free standing and comprises :
-
oil pump
- motor
- oil filter(s)
- air bottle
The unit is assembled for floor mounting (see
diagrams Distillate Oil Pumping Set on Page C.12
and Oil Pumps on Page C.9). This unit is designed
to deliver the oil volume and pressure for the
required burner output.
Filter(s) are an integral part of the burner oil supply
system. The filter(s) should be checked regularly as
failure to do so may result in a drop in oil pressure
to the system.
Pumping/Heating Set For Class E, F and G Fuels
The pump unit is free standing and comprises :
-
oil pump
- motor
- hot oil filter
- cold oil filter(s)
- air bottle
- isolation valve (for residual fuel oil)
- return thermostat
- oil pre-heater tank with thermometer to
record the temperature of the oil at the outlet.
The pre-heater contains three thermostats:
-
High limit thermostat
- Control thermostat
- Low limit thermostat (reverse acting)
The return thermostat is fitted in the return oil line
and will override the burner firing controls and start
the burner oil pump in order to maintain the
correct oil temperature in the nozzle and burner
pipework.
The thermostats should be set to the temperatures
specified in the Table forming part of diagram
Residual Oil Pumping Set on Page C.13.
The unit is pre-assembled on a base plate for floor
mounting (see diagrams Residual Oil Pumping Set
on Page C.13 and Oil Pumps on Page C.9). This
unit is designed to deliver the oil volume at
temperature and pressure for the required burner
output.
The pump should not be started when the oil is
cold as this can lead to damage to the pump and
couplings. The oil must be supplied and
maintained at the temperature and pressure given
in the Table on Page B.8.
Filter(s) are an integral part of the burner oil supply
system. The filter(s) should be checked regularly
as failure to do so may result in a drop in oil pressure
to the system.
Oil Control Train
The oil control train consists of a high pressure fuel
pump driven by the burner fan motor.
The oil nozzle throughput is controlled by a
variable orifice regulator situated in the return
supply oil line, and actuated by the Modulating
Unit described below. Solenoid operated normally
closed valves in the feed and return lines act as
the safety shut off for the nozzle.
Oil Manifold
The oil manifold block is located on the burner
casing and incorporates pressure gauges to measure
pump and spill pressures.
Solenoid Valve
For burners designed for distillate oil firing there is
a solenoid valve which is ‘normally-closed’ and is
located between the manifold block and the oil
lance (see diagram on Page C.10).
There is no solenoid valve fitted when the system
is designed to fire residual oil (see diagram on Page
C.11).
Inner Assembly Gun
The oil inner assembly gun is located in the middle
of the head casing assembly of the burner. Its
primary function is to carry oil from the oil pump
to the nozzle and to recirculate the oil back through
the spill regulating valve.
The spill-back atomiser utilises a spring loaded
orifice shut-off needle that is closed by the spring
of the actuating piston of the burner lance. This
guarantees a reliable shut-off under any condition.
This piston is driven by the supply pressure, via a
branch pipe, and controlled by a solenoid valve.
The needle opens by means of a spring and moves
to the correct position governed by a fixed stop on
the needle itself.
During the pre-purge period the needle holds the
orifice closed and the fuel oil circulates through
the lance and the atomiser under the set supply
and return pressure. When the solenoid is actuated,
immediate oil atomisation and ignition are
achieved.