This Standard Practice covers 1/4 turn eccentric cast iron plug valves having flanged@ threaded@ mechanical joint@ or grooved end connection. This standard is intended for resilient seated valves with circular@ rectangular@ or other geometric seat configuration having no visible evidence of leakage. The size range covered is NPS 3 through 72. Typical applications are sewage@ sludge@ waste water@ and water service. The manufacturer should be consulted for other applications. Conditions of water hammer@ hydraulic pulsation and excessive operating noise are results of the system design rather than valve design and require special design and construction considerations.