工业阀门批发供应商

Industrial valve types and standards

Industrial valves are classified by their operating mechanism and application: ball valves — a spherical ball with a bore controls flow by rotating 90° between open and closed positions; full bore or reduced bore; rising or non-rising stem; manual, pneumatic, or electric actuation; used for isolation in gas, oil, water, and chemical services; rated to ANSI Class 150–2500 or PN10–PN400 pressure classes; butterfly valves — a disc rotates 90° in the flow path; compact and lightweight; concentric, double-eccentric (high-performance), or triple-eccentric (metal seat) designs; used for large-diameter isolation and flow control in water, HVAC, and process piping; gate valves — wedge gate moves perpendicular to flow to open/close; rising or non-rising stem; low pressure drop when fully open; used for isolation in piping systems where infrequent operation is expected; globe valves — globe-shaped body with plug or disc for throttling and flow control; suitable for frequent operation; used where flow regulation is needed; check valves — prevent reverse flow — swing check, lift check, dual-plate wafer check types; control valves — modulating valves actuated by pneumatic (4–20mA), electric, or hydraulic signal to regulate flow, pressure, temperature, or level — Emerson Fisher, Flowserve, Samson (Germany) are the leading brands; solenoid valves — two-way or three-way electrically operated pilot valves for pneumatic or hydraulic circuits; Festo, Parker, ASCO, and Bürkert are key manufacturers. Key standards: API 6D (pipeline valves — full bore ball and gate valves); API 608 (metallic ball valves); API 600/6FA (fire-safe design for ball, gate, globe, and check valves); BS 6755 / ISO 10497 (fire testing of quarter-turn and check valves); ASME B16.34 (valves for pressure-temperature ratings); PED (Pressure Equipment Directive, 2014/68/EU — required for valves on European process equipment above minimum size/pressure thresholds).