CE Designations
...and how to make sense of them
Temperature Rating
Maximum temperature (°C) for continuous use of the flue. T450 is suitable for multifuel. T200 is suitable for gas and oil.
Pressure Rating
Expressed as N for negative pressure applications, P for positive pressure and H for high positive pressure. Maximum allowed leakage rates are as defined below.
For most applications, N1 is suitable for conventional negative pressure boiler installations. P1 is required for most positive pressure and fan flued boilers. H is for high pressure applications e.g. diesel generators, when the leakage rate is normally subject to specifier requirement.
Condensate Resistance
Suitability for wet or dry operation. W designates ability to contain condensate within the flue, i.e. operating in the wet and dry conditions created by condensing appliances. D designates ability to operate under dry conditions only, usually meaning a flue gas temperature high enough to avoid condensate formation.
Corrosion Resistance
This is fuel dependent as follows:
V1 Tested and approved as resistant to attack from products of combustion from gas.
V2 Tested and approved as resistant to attack from products of combustion from light oil (sulphur content up to 0.2%) and natural wood.
V3 Tested and approved as resistant to attack from products of combustion from heavy oil (sulphur content >0.2%), solid fuels and peat.
Vm Not tested and approved but rating declared by the manufacturer.
Liner Material Specification
Two features are specified, firstly a code for the minimum material grade and secondly material thickness:
Normally liners expected to withstand the corrosion effect of multifuel, wood or heavy oil are made with 316L. Light oil is less corrosive and normally 304 has proved adequate in dry conditions, but in the
increasingly common wet conditions created by high efficiency boilers, a higher grade is required (316L).
Soot Fire Resistance
Expressed as either G, with soot fire resistance or O, without, followed by the declared minimum distance to combustibles expressed in mm. To obtain the G classification, means that the product has been tested at 1000°C for 30 minutes and remains intact and the temperature of combustible material at the designated distance does not exceed 100°C at T. amb. 20°C. Products with O classification mean the product is not rated as soot fire resistant. Normally this will occur with low temperature applications such as condensing gas boilers, where lip seals are used, which would not withstand a soot fire.
Distance to Combustibles
Defined in soot fire resistance above. This definition is easily misunderstood. It has to be read in conjunction with the soot fire resistance classification and is NOT a stand alone classification. The CE Designation Marking System is laid out as follows:
