Unigas HTP2000 Installation Manual page 22

PART II: INSTALLATION
Installation diagram of light oil pipes
PLEASE READ CAREFULLY THE "WARNINGS" CHAPTER AT THE BEGINNING OF THIS MANUAL.
The burner is supplied with filter and flexible hoses, all the parts upstream the filter and downstream the return flexible hose, must be
installed by the customer. As far as the hoses connection, see the related paragraph.
Key
1 Burner
2 Flexible hoses (fitted)
3 Light oil filter (fitted)
4 Automatic interceptor (*)
5 One-way valve (*)
6 Gate valve
7 Quick-closing gate-valve (outside the tank or boiler rooms)
Depending on the installed pump, it is possible to design the plant for single or double pipe feeding line
Single-pipe system: a single pipe drives the oil from the tank to the pump's inlet. Then, from the pump, the pressurised oil is driven to
the nozzle: a part comes out from the nozzle while the othe part goes back to the pump. In this system, the by-pass plug, if provided,
must be removed and the optional return port, on the pump's body, must be sealed by steel plug and washer.
Double-pipe system: as for the single pipe system, a pipe that connects the tank to the pump's inlet is used besides another pipe that
connects the pump's return port to the tank, as well. The excess of oil goes back to the tank: this installation can be considered self-ble-
eding. If provided, the inside by-pass plug must be installed to avoid air and fuel passing through the pump.
Burners come out from the factory provided for double-pipe systems. They can be suited for single-pipe system (recommended in the
case of gravity feed) as decribed before.To change from a 1-pipe system to a 2-pipe-system, insert the by-pass plug G (as for ccw-rota-
tion- referring to the pump shaft).
Caution: Changing the direction of rotation, all connections on top and side are reversed.
About the use of fuel pumps
Do not use fuel with additives to avoid the possible formation over time of compounds which may deposit between the gear teeth,
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thus obstructing them.
After filling the tank, wait before starting the burner. This will give any suspended impurities time to deposit on the bottom of the
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tank, thus avoiding the possibility that they might be sucked into the pump.
On initial commissioning a "dry" operation is foreseen for a considerable length of time (for example, when there is a long suction
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line to bleed). To avoid damages inject some lubrication oil into the vacuum inlet.
Care must be taken when installing the pump not to force the pump shaft along its axis or laterally to avoid excessive wear on the
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joint, noise and overloading the gears.
Pipes should not contain air pockets. Rapid attachment joint should therefore be avoided and threaded or mechanical seal jun-

ctions preferred. Junction threads, elbow joints and couplings should be sealed with removable sg component. The number of jun-
ctions should be kept to a minimum as they are a possible source of leakage.
Do not use PTFE tape on the suction and return line pipes to avoid the possibility that particles enter circulation. These could depo-
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sit on the pump filter or the nozzle, reducing efficiency. Always use O-Rings or mechanical seal (copper or aluminium gaskets) jun-
ctions if possible.
An external filter should always be installed in the suction line upstream the fuel unit.
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ATTENTION: before the burner first start, it is mandatory to fill the adduction pipes with diesel fuel and bleed out residual
air bubbles. Prior to switching on the burner, check direction of rotation of the pump motor by briefly pressing the starter
switch; ensure there are no anomalous sounds during equipment operation, and only then turn on the burner. Neglect to
comply with this requirement will invalidate the burner warranty.
From tank
To tank
Fig. 13 - Double-pipe system
(*) Only for installations with gravity, siphon or forced
circulation feed systems. If the device installed is a
solenoid valve, a timer must be installed to delay the
valve closing.
The direct connection of the device without a timer
may cause pump breaks.
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