This Standard specifies the characteristics of wafer type rubber-seated butterfly valves (hereafter referred to as “valves”) to be used for piping for general equipment such as mechanical equipment, building equipment and water treatment. However, this does not apply to those for ships and water service facility use to which other standards apply. When the application of various laws and regulations, and the approval and authorization are required, these shall be observed, separately. For reference, the designation items of purchase specification of valves and items of previous arrangement at the time of contract are given in Annex B, and the precautions on use are given in Annex C.