Hamworthy F40V Installation, Commissioning And Operating Instructions page 54

satisfactory performance in all applications. Consideration must be given to the correct calculation of the
required flue size. If in any doubt consult Hamworthy Heating Ltd who can supply a full flue design and
installation service.
C1.2 Waste Gas Volume and Temperature.
It is recommended that the volume and temperature of the waste gases used for design of the flue system are as
given in the above tables.
C1.3 Materials.
Materials used for the flue system must be mechanically robust, resistant to internal and external corrosion, non-
combustible and durable under the conditions to which they are likely to be subjected. Consideration must be
given to avoid possible freezing of condense water traps and pipe work.
C1.4 Suction
The flue system must be designed acknowledging that there is a positive pressure generated by the boiler combustion
fan. Refer to table Appendix C.
The flue system must be designed to limit the max. suction (cold) to 30Pa negative, measured at the connection to the
boiler. If the suction is greater than 30Pa, refer to HHL technical. This condition must then be checked hot and with all
boilers firing, the max. pressure at the connection to the boiler should be 150Pa positive.
In the event that the flue system when hot does generate a suction, the max. suction is 100Pa.
Any stabiliser fitted must be in or close to the vertical chimney.
C1.5 Disconnection
Provisions should be made for disconnection of the flue pipe for servicing. It is advisable that bends are fitted
with removable covers for inspection and cleaning as appropriate.
WARNING: THE FLUE SYSTEM MUST BE SELF SUPPORTING AND NOT PRESENT
A RISK TO PEOPLE IN OR AROUND THE BUILDING.
C1.6 Flue Discharge
The flue system must ensure safe and efficient operation of the boiler to which it is attached, protect the
combustion process from wind effects and disperse the products of combustion to the external air. The flue must
terminate in a freely exposed position and be so situated as to prevent the products of combustion entering any
opening in a building. Where the flue diameter is less than 204mm (8") diameter a terminal must be fitted. Where
the flue is of a larger size, consideration should be given to the fitting of a flue discharge terminal or grille to stop
ingress of birds etc.
C1.7 Surface Temperatures
Combustible materials in the vicinity of the boiler and flue shall not exceed 65°C during boiler operation. The flue
shall not be closer than 50mm to any combustible material, except where it passes through such material with a
non-combustible sleeve when the air gap may not be less than 25mm.
C1.8 Location
The flue system must not be placed or fitted where there is undue risk of accidental damage to the flue pipe or
undue danger to persons in the vicinity. Check that the flue and chimney are clear from any obstruction. Fleet
boilers are suitable for installation in a balanced compartment in accordance with the requirements of BS 6644.
Consult Hamworthy Heating Technical Department for help or assistance if in doubt.
For B23 applications the HHL air inlet filter (Pt. No. 532812008) MUST be used.
C1.9. Condensate Discharge
Due to the high thermal efficiency of the boiler, condensation will occur within the boiler casing during firing from
cold conditions. A drain with an integral trap is fitted to each module suitable for connection to a 40mm plastic
waste pipe (not Hamworthy Heating Ltd supply), which must be connected to a tundish (not Hamworthy Heating
Ltd supply). Discharge piping from a tundish should be of synthetic material due to the mild acidity of the
condensate (pH3-5), with all discharge piping having a minimum fall of 50mm/m away from the boiler.
Consideration should be given to possible freezing of condense water traps and pipe work. This must be avoided
at all times by routing pipe work within the building, where possible.
In addition to the above, should the plastic flue system supplied discharge into a metallic chimney system, any
condensate formed in the chimney MUST NOT drain back through the plastic components to the boiler. A
separate drain for the chimney system must be provided.
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HAMWORTHY HEATING LTD FLEET V series 500001213/G