Time：2016-04-13 19:41:10 Views：
Valve fluid transfer system is a pipeline control unit, which is used to change the channel section and flow direction of medium, with the diversion, close, adjust, throttle-return, pressure relief features such as streaming or overflow.
For fluid control valves, valve from the simplest to the most complex automatic control system used in a variety of valves, its many varieties and specifications, the valve nominal diameter from large to tiny instrument valve Path up to 10m of industrial pipeline valves. Valve can be used to control water, steam, oil, gas, slurry, corrosive medium, the liquid metal and radioactive fluids and other types of fluid flow, working pressure valve to 1000MPa from 1.3х10MPa the high pressure, Working temperature from -269 ℃ to 1430 ℃ ultra-low temperatures. Control valves can use a variety of transmission modes such as manual, electric, hydraulic, pneumatic, worm gear, electromagnetic dynamic, electromagnetic - hydraulic, electro - hydraulic, gas - hydraulic, spur gears, bevel gear drive etc.; can be pressure, temperature or other forms of sensor signals under, according to the requirements of scheduled actions, or do not rely on a simple sensor signals to open or close the valve to rely on drivers or auto body parts to make opening and closing movements , sliding, rotating pendulum, or rotary movement, thus changing the size of its flow area to achieve its control function.
I use the valve
Valve is a pipe attachment, which is used to change the channel section and flow direction of medium, control movement of a device transmission medium, with diversion, cut-off,regulating,throttling, just back, diversion or overflow relief and so on. Specifically, the valve has the following purposes:
1.1 cut-off valve types: connect or disconnect the line in the media sections. Such as gate valve, globe valve, ball valves, plug valves,diaphragm valves, butterfly valves and so on.
1.2 regulating valve: regulate the flow pipe and pressure in the medium. Such as throttle, regulating valve, reducing valve, safety valve and so on.
1.3 shunt valves: changes in the flow direction of medium pipeline for distribution, separation or mixed media. Such as the distribution of valves, three plug, three or four-way ball valves, steam traps, etc..
Category II valve
Wide variety of valves, with various types of equipment and performance of the continuous improvement process, valves are still increasing, but in general can be divided into two main categories:
2.1 Automatic Valves Rely on media (liquid, gas, steam, etc.) their ability to self-movement of the valve. Such as the safety valve, check valve, valve, steam traps, hydraulic control valves, emergency shut-off valve, exhaust valve and so on.
2.2-driven valve With manual, electric, hydraulic and pneumatic valves to control. Such as gate valve, globe valve, throttle valve, butterfly valve, ball valve,balance valve, plunger valve, plug valve and so on.
Valves rely on open and close automatically or drive mechanism so that pieces of lifting, sliding, rotating pendulum, or back to convey movement, thereby changing the size of its flow area, in order to achieve its control function.
In addition, the valves have the following classification.
2.3 Structure of sub-
Closed Kai pieces according to the moving direction relative to the seat can be divided into:
Door-shaped section 2.3.1: Closed Kai pieces move along the centerline of the valve seat.
2.3.2 Gate-shaped: Closed Kai piece seat along the center line perpendicular to the direction of movement.
2.3.3 cock and ball: opening and closing parts are piston or sphere around its own axis of rotation.
2.3.4 Swing type: opening and closing parts of the axis of rotation around the outside seat.
2.3.5 Butterfly: opening and closing parts of the disk, rotating around the axis of the valve (middle type) or a seat outside the axis of rotation (eccentric)
2.3.6-shaped slide valve: opening and closing piece in the direction perpendicular to the channel slide up.
2.4 divided by control method: According to the different control methods can be divided into:
2.4.1 Manual Valves - with hand wheels, handles, wrenches, lever or sprocket and so on. From the human to manipulate the valve, when the need to pass when a large torque can be mounted worm gear, gear deceleration devices.
2.4.2 Electric Valve - With motor, electromagnetic, or other electrical to manipulate the valve.
2.4.3 hydraulic or pneumatic valves - by means of liquid (water, oil, liquid medium) or the gas control valve.
2.4.4 Automatic valves - to rely on media (liquid, gas, steam) their ability to self-action of the valve.
III classification by the main parameters
3.1 by pressure points:
3.1.1 Vacuum Valve - working pressure lower than standard atmospheric pressure of the valve, the absolute pressure is less than 0.1MPa (760mm Hg or higher) of the valve, usually mm water column (mmH2O) or millimeters of mercury (mmHg), said pressure.
3.1.2 Low Pressure valve - the valve nominal pressure PN ≤ 1.6MPa.
3.1.3 medium pressure valve - the valve nominal pressure PN2.5 ~ 6.4MPa (25 ~ 64kg).
3.1.4 High Pressure Valve - PN PN10.0 ~ 80.0MPa valves (100 ~ 800kg).
3.1.5 High Pressure valve - the valve nominal pressure ≥ 100MPa (1,000 ~ 10,000 kg).
3.2 Medium temperature points:
3.2.1 Room Temperature Valve - -40 ℃ ≤ t ≤ 120 ℃ valve.
3.2.2 Medium Temperature Valve - 120 ℃ ≤ t ≤ 450 ℃ valve.
3.2.3 High temperature valve - t> 450 ℃ valve.
3.2.4 The low temperature valve - -100 ℃ ≤ t ≤ -40 ℃ valve.
3.2.5 ultra-low temperature valve - t <-100 ℃ valve.
3.3 Classification by Body Material:
Body Material Material
Non-metallic materials, ceramic glass fiber reinforced plastic
Metal alloy of copper-lead alloy aluminum alloy Monel alloy
Low alloy cast iron with high carbon steel alloy
3.4 Classification by body lining material:
Body lining material
Copper alloy steel alloy metal fluoroplastics
Non-metallic materials, rubber, rubber, rubber lined fluorine plastic nylon
Nominal diameter by 3.5 points:
3.5.1 small-caliber valve - nominal diameter DN <40mm valve.
3.5.2 of the valve diameter - nominal diameter DN50 ~ 30mm valve.
3.5.3 Large Diameter Valves - nominal diameter DN350 ~ 1200mm valve.
3.5.4 large diameter valves - nominal diameter DN> 120mm valve.
3.6 points and pipeline manner:
3.6.1 Thread the valve - the valve body with an internal thread or external thread, and pipe thread connection used.
3.6.2 flange valve - the valve body with a flange, and pipe with flange connection.
3.6.3 Welding connection valve - the valve body with welded joints, and pipes welded.
3.6.4 on the wafer valve - the valve with a double-headed bolt flange connection between the pipe.
3.6.5 clamps to connect the valve - the valve body with a clip mouth lines, and pipeline connections with clamps.
3.6.6 Connect the valve sleeve - with sleeve and pipe connections.
General classification of valve IV
This classification not only by theory, the role of the structure divided by another, is the domestic and international classification of the most used.
Generally divided into: gate valve, globe valve, throttle, valve, ball valve, butterfly valve, safety valve, check valve, and the bottom valve,diaphragm valve, drain valve, steam traps, piston valve, regulating valve.