This Standard specifies requirements for PN 10, PN 16, PN 21 and PN 35 manually operated resilient-seated double-flanged butterfly valves for waterworks purposes, with a maximum operating temperature of 40°C. This Standard covers the following:Manual actuators, gearboxes and standard spindle caps.Water supply applications, including drinking water, recycled water and screened wastewater.Valves of the following nominal sizes:Seal on discDN 300 to DN 2000.Seal in bodyDN 80 to DN 2000.Seal on bodyDN 80 to DN 2000.The capability of the valves to be fitted with electric, hydraulic or pneumatic actuators and operated using portable actuators.The ability of valves to be subjected to buried and continuously immersed applications, where required, with the use of suitable options. For purchasing guidelines, see Appendix B.