Specific classification methods and characteristics of control valves
There are many types of control valves. With the continuous increase in various complete sets of equipment, and multiple classification methods, the types of control valves continue to increase due to continuous improvements in process flow and performance, and there are many ways to classify them.
①Adjustable type;
② Cut-off type;
③Adjust the cut-off type.
(3) Classification according to the form of movement: ① straight stroke; ② angular stroke.
(4) Classification according to the shape of the valve core: ① flat-shaped valve core; ② column-shaped Fujian core; ③ window-shaped valve core: ④ sleeve-shaped mesh core; ⑤ multi-stage valve core; ⑥ deflection-shaped valve core; ⑦ butterfly-shaped valve core; ⑧ spherical valve core.
(5) Classification according to flow characteristics: ① straight line; ② equal percentage; ③ parabola; ④ quick opening.
(6) Classification according to the form of the upper valve cover: ① Ordinary type: ② Heat dissipation (absorption) type: ③ Long neck type; ④ Bellows sealed type.
2. Electric regulating valve
(1) Classification according to the form of electric actuators: ① Angular stroke; ② Straight stroke; ③ Multi-turn type. (2) Classification by accessory form ① servo amplifier; ② limit switch.
(3) Classified according to flow characteristics: ① straight line; ② equal percentage; ③ parabola; ④ quick opening.
(4) According to the form of the upper cover, it is classified into ① ordinary type; ② loose (suction) cushion type; ③ long neck type; ④ bellows sealed type.
3. Manual regulating valve
Classification according to the shape of the valve core: ① cone shape; ② plunger shape; ③ window shape; ④ sleeve shape: ⑤ multi-stage shape; ⑥ deflection shape; ⑦ butterfly shape; ⑧ spherical or hemispherical.
In addition, there are (electric) hydraulic control valves and intelligent control valves, etc.
3-Carbon steel and stainless steel material,
Pneumatic is divided into membrane switch type, membrane regulating type, membrane
1-Switch type pneumatic regulating valve
1.1.1 Classification by driving method
1. Self-operated regulating valve: It uses the energy of the medium to be regulated (liquid, air, steam, natural gas, etc.) to realize medium temperature, pressure, wave and micro-pressure regulating valve, etc. The most automatically adjusted valves, such as self-operated pressure regulating valve, self-operated temperature regulating network, self-operated differential pressure regulating pottery self-operated
2. Driven control valve: a control valve operated by manual, electric or pneumatic control, such as pneumatic control valve, electric control valve, (electric) hydraulic control valve, intelligent control valve, manual control valve, etc.
1.1.2 Classification by main technical parameters
1. Classification by nominal size
1) Small diameter control valve is a control valve with nominal size.
2) The nominal size of the medium diameter control valve is DN50-DN300.
3) Large diameter control valve with nominal size ≥ DN350.
2. Classification by nominal pressure
(1) Vacuum regulating valve: a regulating valve whose working pressure is lower than the standard atmospheric pressure.
(2) The nominal pressure of the low-pressure regulating valve is ≤PN16.
(3) Medium pressure regulating valve is a regulating valve with a nominal pressure of PN25 ~ PN63.
(4) High-pressure regulating valve is a regulating valve with a nominal pressure of PN100 and PN800. This class will come from Shang No. 1 (5) ultra-high pressure regulating valve with nominal pressure > PN800.
3. Classification according to medium working temperature
(1) High temperature regulating valve 1>450C regulating valve.
(2) Medium temperature control valve 120C <1≤450T control valve.
(3) Normal temperature regulating valve 29C ≤ 1 ≤ 120C regulating valve.
(4) Low temperature regulating valve – 100C ≤ l ≤ -29 centimeters regulating valve.
(5) Ultra-low temperature regulating valve t<- 100C regulating valve.
4. Classification according to valve body material:
(1) Non-metallic material control valves such as ceramic control valves, fiberglass control valves, plastic control valves, etc.
(2) Metal material control valves such as copper alloy control valve, aluminum alloy control valve, lead alloy control valve, titanium alloy control valve, Monel alloy control valve, Hastelloy alloy control valve, cast iron control valve, carbon cast steel control valve, low alloy steel control valve, high alloy steel control valve, stainless steel control valve.
(3) Metal valve body lined control valves such as lead-lined control valves, polytetrafluoroethylene-lined control valves, enamel-lined control valves, etc.
5. Classification according to the connection method with the pipeline
(1) Flange connection regulating valve is a regulating valve with a flange on the valve body and a flange connection with the pipeline.
(2) Threaded connection control valve is a control valve with internal or external threads on the valve body, and is connected to the pipeline by screw thread.
(3) Welded connection regulating valve: The valve body has a welding port and is welded to the pipeline.
(4) Clamp connection control valve is a control valve with a clamp port on the valve body and a clamp box connection with the pipeline.
(5) The control valve is connected with a ferrule and is connected to the pipeline with a ferrule.
6. Classify according to control methods
(1) Manual regulating valve: A regulating valve controlled by manpower with the help of a handwheel, handle, lever or sprocket. When Xiaohui transmits large torque, reduction devices such as worm gears and gears can be used.
(2) Electric control valve is a control valve controlled by an electric motor or other electrical device. Huzhou Aoshi Xihai Yinxudadai (3) Pneumatic control valve is a control valve controlled by air pressure.
1.1.3 Classification by use and function
2-Proportional pneumatic diaphragm regulating valve
1. Regulating valve with automatic flow adjustment: The flow rate of the liquid sent to the pipeline by the pressure boosting equipment can be measured with the help of a flow transmitter. transmission
The standard output signal of the regulator is transmitted to the regulator, and the control signal generated by the regulator acts on the regulating valve through the valve positioner. When there is a disturbance, if the flow rate in the pipeline drops, the regulator will open the regulating valve until the original flow rate is restored.
2. Regulating valve for automatic liquid level adjustment: The signal of the liquid level in the tank is transmitted to the regulator by the transmitter. The output value is compared with the given value in the regulator, and the regulator output signal acts on the regulating valve. When the liquid level increases, the flow rate decreases; conversely, when the liquid level decreases, the flow rate increases.
3. Regulating valve with automatic pressure adjustment: a regulating valve that keeps the pressure constant in the system or tank.
4. Regulating valve with automatic temperature adjustment. (A regulating valve that maintains a certain temperature in the process)
1.1.4 Classification by structural type
1. Pneumatic regulating valve
(1) Classification according to the form of pneumatic actuators
1) Membrane actuator. It is divided into direct-mounted type (direct action and reaction) and side-mounted type (direct action and reaction).
2) Piston actuator. It is divided into proportional formula (direct action and reaction) and two-position formula.
3) Long stroke actuator.
4) Rolling film actuator.
(2) Classification according to adjustment form
switch type and piston regulating valve type.
