BS EN 16475-1:2020 pdf free download – Chimneys一Accessories Part 1: Chimney silencers一Requirements and test methods.
3.8
nominal velocity
velocity in a duct which characterises the velocity used in the test
Note 1 to entry: The actual test velocity can differ from the nominal velocity, because the actual inside diameter differs from the nominal diameter.
3.9
continuously welded silencer
housing is welded according to a continuous welding procedure that allows get at least Hi leakage class
3.10
non-continuously welded silencer
silencer not manufactured in accordance with 3.9
EXAMPLE An example for a non-continuously welded silencer is a modular silencer.
4 Product characteristics
4.1 General
The silencer shall fulfil the following requirements against temperature, condensate, corrosion resistance and soot fire resistance capability appropriate to the designation.
4.2 Dimensions and tolerances
The thickness of material of the silencer shall be not less than that declared.
The declared internal dimensions of the flue connection shall not vary by more than ± 5 mm from the nominal size. The measured internal dimension of the flue connection shall be not less than the declared dimension.
4.3 Mechanical resistance and stability
4.3.1 Compressive strength
The silencer shall withstand a load of at least four times the declared design load, If declared, the silencer shall he tested in accordance with 5.3.1.
If the design load is not declared and the silencer is used in vertical position, a support shall be used on top of the silencer.
If used in horizontal position or on top of the chimney, the design load does not have to be declared.
4.4 Thermal performance
4.4.1 Reaction to fire
The reaction to fire shall be declared. It shall be assessed on basis of EN 1350 1-1.
NOTE Materials which are by default classified Al (see Commission Decision [96/603/EC (2)]) need no further testing.
4.4.2 Fire resistance (internal to external)
4.4.2.1 General
The distance to combustible material, the gas tightness and the insertion loss of the silencer shall be declared.
4.4.2.2 Heat stress
The silencer shall be tested in accordance with 5.4.1 for the designated temperature class, see Table 3.
The silencer shall be designated 0, if the requirements of 4.5.1 and 4.10 are met.
4.4.2.3 Sootfire resistance
The silencer shall be tested in accordance with 5.4.2.
The silencer shall be designated G, if the requirements of 4.5.1 and 4.10 are met.
The silencer shall be designated As, if it is tested in accordance with 5.4.2 and only the declared insertion loss of 4.10 is no longer fulfilled.
4.4.2.4 Distance to combustible
The minimum distance xx in mm of the silencer to combustible material shall be declared:
a) O(xx)M stands for “measured value” as determined in accordance with the test method in EN 1856-2:2009, A.7.3.3. When related to ambient temperature of 20° C, the maximum surface temperature of combustible materials adjacent to the test silencer shall not exceed 85° C at the distance declared.
b) As(xx)M, G(xx)M stands for “measured value” as determined in accordance with the test method in EN 1856-2:2009, A.7.3.3. When related to ambient temperature of 20 °C, the maximum surface temperature of combustible materials adjacent to the test silencer shall not exceed 85 °C during heat stress test and shall not exceed 100 °C during the heat shock test, both at the distance declared.
c) O(xx)NM, As(xx)NM, G(xx)NM stands for “not measured value” calculated as at least three times their nominal diameter but not less than 375 mm (as specified in EN 15287-1:2007+A1:2010, 4.3.9.3, paragraph 3, first sentence for connecting flue pipes naturally ventilated).