BS EN 437-2021 Test gases – Test pressures – Appliance categories.
6.12.3 Appliances designed for use on second family gases only
Category IZK: appliance using only gases of group H of the second family at the prescribed supply pressure.
Category IZL: appliances using only gases of group L of the second family at the prescribed supply pressure.
Category li: appliances using only gases of group E of the second family at the prescribed supply pressure. Category lag.: appliances using only gases of group E of the second family, and operating with a pressure couple without adjustment of the appliance. The appliance gas pressure regulating device. ills exists. Is not operative at pressures In between the Iwo normal pressures of the pressure couple.
Category I appliances using only second family gases at the prescribed supply pressure and that automatically adapt to all gases of the second faintly.
Category l2R: apphanLes having a pressure regulator whkh can br manually adjusted in order to utilize each of the following gas groups: H, E. L IC and LL (see also Table 0.6).
61.2.4 Appliances designed for use on 3 family gases only
Category Ii,p: appliances capable of usrng the third ramily gases (propane and butane) at the prescribed supply pressure.
Category 13.: appliances capable of using gases of the third family (propane and butane) and operating with a pressure couple without adjustment of the appliance. However, for certain types of appliances specified in the particular standards, adlustment of the primary combustion air may be permitted when changing from propane to butane and vice versa. P4o gas pressure regulating device Is permitted on the appliance. Category lp appliances using only gases of group P of the third family (propane) at the prescribed supply pressure.
Category l3B: appliances using only gases of group H of the third Family (butane) at the prescribed supply pressure.
Category lpt: appliances having a pressure governor using all the gases of the third family which can be adjusted manually in order to utilize the vanous gases ota group of the third family under the local condition of distribution (see Table 9.7).
6,13 Category II
6.1.3.1 General
Appliances of category II are designed for use on gases of two families
6.1.3.2 Appliances designed for use on gases olthe first and second families
Category II1.2H: appliances capable of using gases of group a of the first family and gases of group H of the second family. The first family gases arc used under the same conditions as for category 111.The second Family gases are used under the same conditions as for category 12*
6.1.3.3 Appliances designed for use on gases of the second and third famIlies
Category ll2H31/VZ appliances capable of using gases of group H of the second family and gases of the third family. The second family gases arc used under the same (unditionc as for category l. The third family gases are used under the came conditions as for category 1p.BS EN 437 pdf download.