This European Standard covers the vapour transfer valve, used for the transfer of vapour between the tank compartment and the pipework connecting to the vapour collection adaptor. This European Standard specifies the performance requirements and the critical dimensions of the vapour transfer valve. It also specifies the tests necessary to verify the compliance of the equipment with this European Standard. The equipment specified by this standard is suitable for use with liquid petroleum products and other dangerous substances of Class 3 of ADR [2] which have a vapour pressure not exceeding 110 kPa at 50 °C and petrol, and which have no sub-classification as toxic or corrosive.