20
Issue 2 14/07/16
3
Installation
3.6 Flue systems
Detailed recommendations for flue installation are given in BS
6644, BS5440 Pt 1 and British Gas publication IM/11 - Flues for
Commercial and Industrial Gas Fired Boilers and Air Heaters.
The flue connection is designed for BS 835 type heavy duty flue,
but light quality flue pipe, mild steel or stainless steel sheet may
be used using the appropriate adapter. Flue pipes etc. shall be
fitted socket-up to keep any condensate within flue and
appliance. Flues up to 200mm diameter should be fitted with a
suitable British Gas Certified terminal.
Fig 4a.
The terminal position is most important and must be at least
1000mm above roof surfaces or at least 600mm above any
parapet and clear of any adjacent obstruction as well as being
clear of any openable windows, ventilators or features which
could allow re-entry of flue products into the building. Pressure
areas should also be avoided to prevent blowdown.
Flue materials, including jointing materials and fittings shall be
asbestos-free, robust, durable, corrosion resistant and non-
combustible and shall comply with BS 5854 and BS 715 or BS
4076 as appropriate, as well as being of a type accepted by the
Local Gas Authority.
When passing up through or adjacent to combustible materials,
measures shall be taken to prevent the temperature of the
combustible material from exceeding 60°C. The flue shall not be
closer than 50mm to any combustible material except when
passing through, when it must be enclosed by a non-
combustible sleeve and separated from the sleeve by not less
than 25mm air space.
Flues shall be of a size not less than specified in Section 2,
Technical Data (i.e. nominal flue size) and fitted so that there is
no risk to persons in the building or from accidental damage.
Fig 4b.
If using an existing brick chimney, it should be swept and lined
and checked for soundness before connecting the flue and
should take the shortest possible route and rise continuously to
the terminal avoiding the use of 90° bends where a change of
direction is required. Horizontal and very shallow runs of flue
should be avoided since they impede the flow of gases and
increase local cooling.
*A minimum of 600mm of vertical flue directly above the draught
diverter should be provided where possible on all natural
draught flue installations. If this dimension cannot be achieved
please contact Andrews Water Heaters.
Fig. 4a
Fig. 4b
Terminal
Roof
600mm*
Split flue clip
1. This flue run
must not be used
2 & 3 are recommended flue runs
1
2
3
1000mm
Minimum
See
See recommendations in BS 6644. BS 5440 Part 1 also
provides useful additional advice.
Note
Please note this is not required where a common flue
header is used on multiple installations.
Содержание 24/39
Страница 1: ......
Страница 65: ...Issue 2 14 07 16 65 Parts List and Illustrations 9 9 10 HIflo models 62 341 and 54 418 440 Natural Gas Fig 34 ...
Страница 69: ...Issue 2 14 07 16 69 Parts List and Illustrations 9 9 15 HIflo LPG models L62 309 L54 399 Fig 31 ...
Страница 112: ...112 Issue 2 14 07 16 ...
Страница 113: ...Issue 2 14 07 16 113 ...
Страница 114: ...114 Issue 2 14 07 16 ...