What are the classifications of valves

Classification by Structural Features

‌Globe Type‌: Closure element moves along the centerline of the valve seat.

‌Gate Type‌: Closure element moves vertically to the centerline of the valve seat.

‌Plug and Ball Type‌: Closure element (plug or ball) rotates around its own axis.

‌Swing Type‌: Closure element rotates around an axis outside the valve seat.

‌Butterfly Type‌: Disc-shaped closure element rotates around an axis within the valve seat.

‌Slide Gate Type‌: Closure element slides perpendicular to the flow direction.

 

Classification by Structural Types

‌Plug Valve, Gate Valve, Globe Valve, Ball Valve‌: Used to start/stop fluid flow in pipelines.

‌Check Valve‌ (including foot valve): Prevents reverse flow automatically.

‌Throttle Valve‌: Regulates fluid flow rate.

‌Butterfly Valve‌: Starts/stops fluid flow; can also regulate flow.

‌Safety Valve‌: Installed on boilers, vessels, and pipelines to automatically release excess pressure beyond set limits, ensuring operational safety.

‌Pressure Reducing Valve‌: Automatically lowers fluid pressure in pipelines/equipment by creating resistance through disc clearance.

‌Steam Trap‌: Automatically discharges condensate in steam pipelines to prevent steam loss/leakage.

 

Classification by Application

‌On/Off Function‌: Connects/cuts off fluid flow (e.g., globe valve, gate valve, ball valve, butterfly valve).

‌Check Function‌: Prevents backflow (e.g., check valve).

‌Regulating Function‌: Adjusts pressure/flow (e.g., control valve, pressure reducing valve).

‌Diversion Function‌: Redirects/distributes fluid (e.g., three-way plug valve, diverter valve, slide valve).

‌Safety Function‌: Releases excess fluid upon overpressure (e.g., safety valve, emergency valve).

‌Specialized Functions‌: Includes steam traps, vent valves, drain valves, etc.

Classification by Purpose and Function

‌Isolation Valves‌: Cut off/connect fluid flow (gate, globe, diaphragm, ball, plug, butterfly, plunger, needle valves).

‌Regulating Valves‌: Adjust flow/pressure (control, throttle, pressure reducing valves).

‌Check Valves‌: Prevent reverse flow (all check valve types).

‌Diverter Valves‌: Separate/distribute/mix fluids (diverter valves, steam traps).

‌Safety Valves‌: Overpressure protection (all safety valve types).

 

Classification by Actuation Method

‌Manual‌: Operated via handwheel, lever, or chain; equipped with worm/gear reducers for high torque.

‌Electric‌: Driven by electric motors or devices.

‌Hydraulic‌: Driven by fluids (water/oil).

‌Pneumatic‌: Driven by compressed air.

 

Classification by Pressure Rating

‌Vacuum Valve‌: Absolute pressure <0.1MPa (760mmHg); pressure units: mmHg or mmH₂O.

‌Low-Pressure Valve‌: Nominal pressure PN ≤1.6MPa (including steel valves ≤1.6MPa).

‌Medium-Pressure Valve‌: Nominal pressure PN 2.5–6.4MPa.

‌High-Pressure Valve‌: Nominal pressure PN 10.0–80.0MPa.

‌Ultra-High-Pressure Valve‌: Nominal pressure PN ≥100.0MPa.

Classification by Media Temperature

‌Standard Valve‌: For media temperatures -40°C to 425°C.

‌High-Temperature Valve‌: For media temperatures 425°C to 600°C.

‌Heat-Resistant Valve‌: For media temperatures >600°C.

‌Cryogenic Valve‌: For media temperatures -40°C to -150°C.

‌Ultra-Cryogenic Valve‌: For media temperatures < -150°C.

 

Classification by Nominal Diameter (DN)

‌Small-Bore Valve‌: DN <40mm.

‌Medium-Bore Valve‌: DN 50–300mm.

‌Large-Bore Valve‌: DN 350–1200mm.

‌Extra-Large-Bore Valve‌: DN ≥1400mm.

 

Classification by Connection Type

‌Flanged Connection‌: Valve body with flanges, connects via pipeline flanges.

‌Threaded Connection‌: Valve body with internal/external threads, connects via threads.

‌Welded Connection‌: Valve body with welding ends, connects via welding.

‌Clamp Connection‌: Valve body with clamp grooves, connects via clamps.

‌Ferrule Connection‌: Connects to pipelines via ferrules.