Full definition
Valve with a plug/disc moving axially against a seat oriented perpendicular to flow, designed for precise throttling. Greater pressure drop than ball/gate valves but superior control capability and tight shutoff. Sizes: 1/2" to 24". Typical Cv: 10-600. Fluids: water, steam, gas, light oils. Temperature: up to 600°C (stainless steel). Actuation: manual, electric, pneumatic. Standards ASME B16.34, API 623. Brands: Flowserve (Valtek), Samson, CIRCOR, Fisher (Emerson).