This Standard specifies requirements for Classes 10, 16, 21 and 35 manually operated resilient-seated wafer, tapped lugged, and flanged butterfly valves for waterworks purposes, with a maximum operating temperature of 40 Degrees Celsius. This Standard covers the following:(a) Manual actuators, gearboxes and standard spindle caps.(b) Water supply applications that include drinking water and recycled water as well as screened wastewater. (c) Valves of the following nominal sizes:(i) Seal-on-disc: DN 300 to DN 2000.(ii) Seal-in-body: DN 80 to DN 2000.(iii) Seal-on-body: DN 80 to DN 2000.(d) The capability of the valves to be fitted with electric, hydraulic or pneumatic actuators and to be operated using portable actuators.NOTE: Purchasing requirements that should be agreed upon at time of inquiry or order are given in Appendix B.