A complete set of valves
1.？ Classification by function and use
( 1)? Block valve: Block valve, also known as closed-circuit valve, is used to connect or cut off the medium in the pipeline. Block 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, is used to prevent the medium in the pipeline from flowing backwards. The bottom valve of water pump suction switch also belongs to the category of check valve.
(3)? Safety valve: The function of safety valve is to prevent the pressure of medium in pipeline or device from exceeding the specified value, so as to achieve the purpose of safety protection.
(4)? Regulating valve: The regulating valve includes regulating valve, throttle valve and pressure reducing valve, and its function is to regulate the pressure, flow and other parameters of the medium.
(5)? Diverter valve: Diverter valve includes various distribution valves and traps. Used to distribute, separate or mix the media in the pipeline.
2。 Classification 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 nominal pressure PN? ≤ 1.6Mpa？ Valve.
(3)? Medium pressure valve: refers to the nominal pressure PN? The valves are 2.5 MPa, 4.0 MPa and 6.4 MPa.
(4)? High pressure valve: refers to the nominal pressure PN? The valve is 10 ~ 80 MPa.
(5)? Ultra-high pressure valve: refers to the nominal pressure? PN≥ 100Mpa valve.
3.？ Classification by working temperature
( 1)? Ultra-low temperature valve: used for the working temperature of medium? T<- 100℃ valve.
(2)? Low temperature valve: used for valves with medium working temperature of-100℃≤t≤-40℃.
(3)? Normal temperature valve: used for valves whose working temperature is -40℃≤t≤ 120℃.
(4)? Medium temperature valve: used for medium working temperature of 120℃
(5)? High-temperature valve: it is used for valves with medium working temperature of t & gt450℃.
4.？ Classification by driving mode
( 1)? Automatic valve refers to a valve that does not need external force to drive, but relies on the energy of the medium itself to make the valve act. Such as safety valves, pressure reducing valves, steam traps, check valves, automatic control valves, etc.
(2)? Electric valve: Electric valve can be driven by various power sources.
Electric valve: A valve driven by electricity.
Pneumatic valve: A valve driven by compressed air.
Hydraulic valve: A valve driven by the pressure of a liquid, such as oil.
In addition, there are combinations of the above driving modes, such as pneumatic-electric valves.
(3)? Manual valve: Manual valve is operated manually with the help of handwheel, handle, lever and sprocket. When the opening and closing torque of the valve is large, the wheel or worm gear reducer can be installed between the handwheel and the valve stem. Universal joints and transmission shafts can also be used for remote operation if necessary.
5.？ Classification by nominal diameter
(1) Small valves: valves with nominal diameter DN≤40mm.
(2) Intermediate diameter valve: a valve with a nominal diameter DN of 50 ~ 300mm.
(3) Large-diameter valves: valves with a nominal diameter of 350 ~ 1200mm.
(4) Extra-large-diameter valves: valves with nominal diameter dn ≥1400 mm. ..
6.？ Classification by structural characteristics
(1) gate valve: the opening and closing parts (disc) are driven by the valve stem to move up and down along the center line of the valve seat;
(2) Plug valve: the opening and closing part (gate valve) is driven by the valve stem and moves up and down along the center line perpendicular to the valve seat;
(3) Plug valve: opening and closing parts (cone plug or ball)? Rotate around your own center line;
(4) Rotary valve: opening and closing parts (disc)? Rotate around the axis outside the seat;
(5) Butterfly valve: opening and closing parts (disc)? Rotating around the fixed shaft in the valve seat;
(6) Slide valve: The opening and closing parts slide in the direction perpendicular to the channel.
The above is Bian Xiao's comprehensive classification of valves, which ends here. I believe that after reading the Bian Xiao Valve Classification Summary, you must have a certain understanding of valve classification. Valve is a mechanical device to control the flow of liquid. There are many kinds of valves on the market. What Xiang Xiao suggested here is that when buying valves, you must keep your eyes open, don't easily believe the rhetoric of unscrupulous merchants, and look for brands and quality before buying. Xiaobian's summary can help everyone.