The valve is in the pipeline flow conveying system control unit, it is used to change pathways of sections and medium flow direction, with diversion, globe, adjusting and throttling, check, tap or overflow discharging pressure etc. Function.
Used for flow control valve, from the most simple globe valve to extremely complex automatic control system used in the various valve, the varieties and specifications is various, the nominal diameter valve from the smallest instrument valve to size of the industrial pipe with valve 10m. The valve can be used to control water, steam, oil and gas, mud, various corrosive medium, liquid metal and various types of radioactive fluid fluid flow, the valve working pressure from the 1000MPa 10MPa to 1.3 х ultrahigh pressure, working temperature of cryogenic from - 269 ℃ high temperature to 1430 ℃. The valve control can use a variety of transmission ways, such as manual and electric, hydraulic, pneumatic, worm and electromagnetic dynamic, electromagnetic - hydraulic, electric, hydraulic, gas, hydraulic, are gear, bevel gear drive, etc.; Can in pressure, temperature or other form, under the action of sensor signals a predetermined requirement action, or not rely on the sensor signals and simple, the valve opens and closes on drivers, or automatic institutions make on-off pieces for lifting, slipping, spinning pendulum or rotary motion, thus changing the size of its port area to achieve their control function.

I valve USES
The valve is a pipeline accessories, it is used to change pathways of sections and medium flow direction, control transfer medium movement a device that has the diversion, globe, adjusting and throttling, check, tap or overflow discharging pressure etc. Function. Specific tell, the valve has the following kinds of USES:
1.1 block valves categories: connected or truncate the medium in pipelines paragraphs. If gate, globe, ball valve and plug valves, diaphragm valve, butterfly, etc.
1.2 regulator categories: adjust the flow and pressure piping intermediary. Such as throttle valve, the regulator, pressure reducing valve, valve, etc.
The purge valve class: 1.3 change flow direction, the pipeline intermediary for distribution, separation or mixed media. Such as distributing, tee plug valves, tee or four ball valve, traps, etc.
II. The valve classification
Type of valve is various, with all kinds of complete sets of equipment process and performance improvement, type of valve is growing, but in general can be divided into two categories:
2.1 automatic valve
Rely on medium (liquid, gas, steam, etc.) the ability of action itself in itself the valve. As a safety valve, check valve, pressure reducing valve, traps, hydraulic control valves, emergency cut-off valve, exhaust valve, etc.
2.2 drive valve
Using manual, electric, hydraulic and pneumatic to manipulate the valve. If gate, globe valve, throttle valve, butterfly, ball valves, balance valve, piston valve and plug valves, etc.
Valve rely on automatic or drive institutions make opening and closing a lift, slipping, spinning pendulum or back to convey movement, change its port area size, in order to realize its control function.
Also, the valves and several classification method.
According to the structure feature points 2.3
According to the relative to shut the rev a seat the direction of the movement can be divided into:
2.3.1 JieMen shape: closed rev pieces of moving along the seat centerline.
Shape: shut the gate 2.3.2 along the vertical to the seating and a centerline direction.
2.3.3 cocks and spherical: opening and closing a is piston or sphere, the axis of rotation around itself.
2.3.4 spin rev shape: opening and closing around the axis of the outside a rotating seat.
2.3.5 wing: opening and closing pieces of disk, the axis of rotation around valve line type) or seat (the axis of rotation (the eccentric type)
2.3.6 slide form: opening and closing a perpendicular to the direction of the channel in the upward sliding.
2.4 press control method points: according to the different control method can be divided into:
Is against 2.4.1 manual valve - with the handwheel, handle, wrench, lever or sprocket, etc. The valve by human to manipulate, when need to pass larger moment, can install worm and gear deceleration device rotor pump etc.
By 2.4.2 electric motors, electromagnetic valve - or any other electrical to manipulate valve.
2.4.3 hydraulic or pneumatic - valve by liquid (water, oil and gas or liquid medium) manipulation of the valve.
2.4.4 automatic valve - rely on medium (liquid, gas, steam) itself but ability. Since action