SCOPE 1.1 This Standard Practice establishes requirements for ductile iron swing check valves with flanged, threaded, mechanical-joint, and push-on ends for general purpose. This Standard Practice covers check valves for installation in pipelines that are horizontal or in pipelines where flow is above horizontal up to vertical with flow upward. 1.2 This Standard Practice describes ductile iron check valves in two categories: 1.2.1 Class rated valves, assigned a pressure and temperature rating as prescribed in an appropriate ASME standard. 1.2.2 Valves limited to Cold Working Pressure (CWP) which are only limited to water service. 1.3 This Standard Practice also includes, directly or by reference, requirements for chemical and physical properties of materials and pressure tests.