Wolf COB Technical Manual And Installation Instructions page 23

Anti-trap valve
General information on the fuel oil
Information on the use of
bio-oil blends:
3062547_201802
16 Oil connection in the single line
system
If the suction height or the max. suction height for sunken tanks is greater than indicated
in the table above, an oil supply unit with an intermediate cylinder is required in the
immediate vicinity of the boiler. It must be possible for the oil to be supplied to the oil
burner pump, which is a separate one on the device, from the intermediate cylinder. It
must be possible to control the oil supply unit independently of the device, i.e. a signal
pick-up on the boiler should not occur for this purpose. When connecting a feed pump
in the supply line, the negative pressure must not exceed 0.5 bar
With negative pressure controlled anti-lift valves, the negative pressure on the inlet
side is increased considerably. It is often difficult to adhere to the maximum permissible
negative pressure of 0.3 bar in the oil line. An electromagnetic control anti-trap valve
shall be used in this case.
The electrical anti-lift devices can be connected to the COB in two ways:
1. The anti-lift valve is connected at output A1. To do this, A1 must be set to 9 (ext. fuel
valve), see HG14.
2. If output A1 is already being used (e.g. for a DHW circulation pump), an adaptor plug
can be used. The adaptor is plugged in between the motor oil pump and the motor plug.
Use low sulphur fuel oil to protect the environment.
1. Permitted bio-oil constituents
The COB (from date of manufacture May 2010) can be operated with fuel oil with up to
10% alternative constituents –B10- to DIN V 51603-6.
2. Bio-oil quality
The bio-oil must comply with EN 14213 when the customer tank is filled.
3. Oil storage tanks
The customer must obtain written confirmation from the manufacturer or supplier
regarding the suitability of the tank for the use of bio-oils, giving the maximum permitted
FAME percentage. It is important to ensure that the tank fittings, seals, filters and oil
lines are also suitable for bio-oil.
4. Tank cleaning
FAME acts as a solvent, removing all deposits and residues in the tank and the oil lines.
For this reason, clean the tank before filling with bio-oil.
5. Storing bio-oil
Bio-oil is a natural product with a lower shelf life than fuel oil EL. Bio-oil must therefore
be stored at low temperatures (ambient temperature between 5 °C and 20 °C) and
protected from exposure to direct sunlight (in the case of plastic tanks in particular).
Up-to-date information indicates that bio-oil should not be stored for longer than one
year, but the mineral oil industry is currently searching for suitable additives to increase
the shelf life.
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