scope:

This European Standard defines the constructional and operational characteristics, the safety requirements and test methods, and the marking of automatic change over devices with a capacity of less than or equal to 100 kg/h and having a maximum regulated pressure of less than or equal to 4 bar for butane, propane or their mixtures only in the vapour phase. Liquefied gases containing methylacetylene and propadiene are not covered by this standard. This European standard also covers safety devices likely to be fitted onto automatic change over devices. The characteristics of these devices are given in annex A. Requirements of this European standard generally cover designs where regulation is in one stage, using a single diaphragm. These requirements do not exclude designs using more than one diaphragm, provided that these diaphragms are integrated in a single automatic change over devices complying with the requirements of this European standard.