API 600 Flanged Gate Valve Cast Steel Class 300

The API 600 flanged cast steel gate valve provides pipeline isolation for water, steam and oil services in refineries, power generation facilities, petrochemical utilities and general industrial plants. Available in Class 150 sizes DN50–DN600 and Class 300 sizes DN50–DN300, it combines WCB body, bonnet and wedge construction with Stellite-hardfaced wedge and seat contact surfaces to improve resistance to sliding wear and galling. A rising stem makes gate travel visible, while the bolted bonnet permits internal inspection and servicing after safe isolation. The listed construction includes a stainless steel stem, graphite packing and bonnet gasket, and an aluminium-bronze stem nut. Raised-face flanges to ASME B16.5 and face-to-face dimensions to ASME B16.10 provide defined interfaces for piping integration and replacement. When fully open, the gate withdraws from the main flow passage, minimizing obstruction and supporting relatively low pressure loss.
These valves are intended for fully open or fully closed duty; sustained throttling can generate vibration and damage the seating surfaces. Class 150 and Class 300 identify pressure classes, with allowable working pressure determined by the applicable material rating and operating temperature. Selection should also establish fluid compatibility, closing differential pressure, required seat tightness and clearance for the extended stem.