BS EN 437:2021 pdf free download – Test gases一Test pressures一Appliance categories.
6.1.2.3 Appliances designed for use on second family gases only
Category 12H: appliance using only gases of group H of the second family at the prescribed supply pressure.
Category 12L: appliances using only gases of group L of the second family at the prescribed supply pressure.
Category 12E: appliances using only gases of group E of the second family at the prescribed supply pressure. Category I2E+: 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, if it exists, is not operative at pressures in between the two normal pressures of the pressure couple.
Category I2N: appliances using only second family gases at the prescribed supply pressure and that automatically adapt to all gases of the second family.
Category I2R: appliances having a pressure regulator which can be manually adjusted in order to utilize each of the following gas groups: H, E, L, K and LL (see also Table B.6).
6.1.2.4 Appliances designed for use on 3rd family gases only
Category 13B/P: appliances capable of using the third family 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, adjustment of the primary combustion air may be permitted when changing from propane to butane and vice versa. No gas pressure regulating device is permitted on the appliance.
Category l3: appliances using only gases of group P of the third family (propane) at the prescribed supply pressure.
Category I3B: appliances using oniy gases of group B of the third family (butane) at the prescribed supply pressure.
Category I3R: appliances having a pressure governor using all the gases of the third family which can be adjusted manually in order to utilize the various gases of a group of the third family under the local condition of distribution (see Table B.7).
6.1.3 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 of the first and second families
Category IIla2H: 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 are used under the same conditions as for category Iia.The second family gases are used under the same conditions as for category 12F1•
6.1.3.3 Appliances designed for use on gases of the second and third families.