Classified by role and use
(1) Shut-off valve: The shut-off valve, also known as the closed-circuit valve, has the effect of turning on or cutting off the medium in the pipeline. Shut-off valves include gate valves, globe valves, plug valves, ball valves, butterfly valves and diaphragms.
(2) Check valve: Check valve, also known as check valve or check valve, its effect is to avoid the backflow of medium in the pipeline. The foot valve of the suction off of the water pump also belongs to the category of check valves.
(3) Safety valve: The effect of safety valve is to avoid the medium pressure in the pipeline or device exceeding the specified value, so as to achieve the intention of safety protection.
(4) Conditioning valve: The conditioning valve category includes conditioning valve, throttle valve and pressure reducing valve, and its effect is the pressure, flow rate and other parameters of the conditioning medium.
(5) Diverter valves: Diverter valves include various distribution valves and traps, etc., the effect of which is to distribute, separate or mix the medium in the pipeline.
Classified by nominal pressure
(1) Vacuum valve: refers to the valve whose working pressure is lower than the standard atmospheric pressure.
(2) Low-pressure valve: refers to the valve with nominal pressure PN ≤1.6Mpa.
(3) Medium pressure valve: refers to the valve with nominal pressure PN of 2.5, 4.0 and 6.4Mpa.
(4) High-pressure valve: refers to the valve with a pressure PN of 10-80Mpa.
(5) Ultra-high pressure valve: refers to the valve with nominal pressure PN≥100Mpa.
Classified by operating temperature
(1) Ultra-low temperature valve: a valve used for medium working temperature t<-100°C.
(2) Cryogenic valve: used for the medium working temperature -100°C≤t≤-40°C valve.
(3) Normal temperature valve: used for medium working temperature -40 °C≤t≤ 120 °C valve.
(4) Medium temperature valve: used for medium working temperature 120°C
(5) High temperature valve: a valve used for medium working temperature t>450°C.
Categorized by drive method
(1) Active valve refers to a valve that does not need to be driven by external force, but relies on the energy of the medium itself to make the valve operate. Such as safety valves, pressure reducing valves, check valves, etc.
(2)
Power Drive Valves: Power drive valves are capable of actuating using a variety of power sources.
Electric valve: A valve that is electrically actuated.
Pneumatic valves: valves actuated by compressed air.
Hydraulic valve: A valve that is actuated by the pressure of a liquid such as oil.
In addition, there are combinations of the above actuation methods, such as pneumatic-electric valves.
(3) Manual valve: The manual valve relies on the handwheel, handle, lever and sprocket, and the valve is operated by manpower. When the opening and closing torque of the valve is large, this wheel or worm gear reducer can be arranged between the handwheel and the valve stem. If necessary, it is also possible to use universal joints and drive shafts for long-distance operation.
Classified according to the nominal diameter
(1) Small bore valve: valve with nominal bore DN≤40mm.
(2) Medium bore valve: valve with nominal bore DN of 50-300mm.
(3) Large diameter valve: the nominal valve DN is 350-1200mm valve.
(4) Extra-large bore valve: valve with nominal bore DN≥1400mm.
Classified by structural characteristics
(1) Cut-off valve: the opening and closing parts (valve discs) are driven by the valve stem to make a lifting movement along the center line of the valve seat;
(2) Plug valve: the opening and closing parts (gate valves) are driven by the valve stem to move up and down along the center line perpendicular to the valve seat;
(3) Plug valve: the opening and closing parts (cone plugs or balls) rotate around their own centerline;
(4) Swing opening valve: the opening and closing parts (valve discs) rotate around the shaft outside the seat;
(5) Butterfly valve: the opening and closing parts (discs) rotate around the fixed shaft in the valve seat;
(6) Spool valve: The opening and closing parts slide in the direction perpendicular to the channel.
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