1, classified by function and purpose

(1) Cut-off class: such as gate valve, globe valve, plug valve, ball valve, butterfly valve, needle valve, diaphragm valve, etc. The shut-off valve, also known as the closed-circuit valve, is used to switch on or off the medium in the pipeline.

(2) Non-return type: such as check valve, check valve is also called check valve, check valve is an automatic valve, its function is to prevent the medium in the pipeline from flowing backward, prevent the pump and drive motor from reversing, and Leakage of container media.

(3) Safety categories: such as safety valves, explosion-proof valves, accident valves, etc.

(4) Adjustment class: such as regulating valve and pressure reducing valve, its function is to adjust the pressure, flow and other parameters of the medium.

(5) Special purpose categories: such as pigging valves, vent valves, blowdown valves, exhaust valves, filters, etc. The exhaust valve is an indispensable auxiliary component in the pipeline system and is widely used in boilers, air conditioners, oil and gas, and water supply and drainage pipes. It is often installed at the commanding heights or elbows to eliminate excess gas in the pipeline, improve the efficiency of the pipeline and reduce energy consumption.

2, classified by nominal pressure

(1) Vacuum valve: refers to a 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 2.5Mpa, 4.0Mpa and 6.4Mpa.

(4) High pressure valve: refers to a valve with a working pressure PN of 10.0Mpa to 80.0Mpa.

(5) Ultra-high pressure valve: refers to the valve with nominal pressure PN≥100.0Mpa.

(6) Filter: refers to the valve with nominal pressure PN of 1.0Mpa and 1.6Mpa.

3, according to working temperature classification

(1) Ultra-low temperature valve: valve for medium working temperature t<;-101 °C.

(2) Cryogenic valve: for valves with medium working temperature -101 °C ≤ t ≤ -29 °C.

(3) Normal temperature valve: used for valves with medium working temperature of -29 ° C < t < 120 ° C.

(4) Medium temperature valve: valve for medium working temperature 120 °C ≤ t ≤ 425 °C

(5) High temperature valve: valve for medium working temperature t > 425 °C.

4, classified by driving method

According to the driving method, it is divided into automatic valve type, power driven valve type and manual valve type:

(1) Automatic valve refers to a valve that does not require external force to drive, but relies on the energy of the medium itself to actuate the valve. Such as safety valves, traps, check valves, automatic regulating valves, etc.

(2) Power-driven valve: The power-driven valve can be driven by various power sources. Divided into electric valve, hydraulic valve and so on. Electric valve: With an electric drive valve. Pneumatic valve: A valve driven by compressed air. Hydraulic valve: A valve that is driven by a liquid pressure such as oil.

In addition, there are combinations of the above several driving methods, such as gas-electric valves.

(3) Manual valve: The manual valve uses manpower to manipulate the valve action by means of the hand wheel, the handle, the lever and the sprocket. When the valve opening and closing torque is large, a gear or worm gear reducer can be provided between the hand wheel and the valve stem. If necessary, you can also use the universal joint and the drive shaft for remote operation.

5. Classified by nominal diameter

(1) Small-diameter valve: a valve with a nominal diameter of DN≤40mm.

(2) Medium diameter valve: a valve with a nominal diameter DN of 50 to 300 mm.

(3) Large-diameter valve: The valve with nominal valve DN is 350-1200mm.

(4) Extra large diameter valve: a valve with a nominal diameter of DN ≥ 1400mm.

6, classified by structural characteristics

The structural characteristics of the valve are divided according to the direction in which the closure member moves relative to the valve seat:

(1) Truss shape: the closing member moves along the center of the valve seat;

(2) cock and ball: the closing member is a plunger or a ball that rotates around its centerline; such as a plug valve, a ball valve

(3) Gate shape: the closing member moves along the center of the vertical valve seat; such as gate valve, gate, etc.

(4) Swing shape: the closing member rotates around the shaft outside the valve seat; such as a swing check valve, etc.

(5) Butterfly shape: the disc of the closing piece rotates around the shaft in the valve seat; such as butterfly valve, butterfly check valve, etc.

(6) Spool shape: The closing member slides in a direction perpendicular to the passage. Spool valve

7, according to the connection method classification
(1) Threaded connection valve: The valve body has internal or external thread and is threadedly connected to the pipe.

(2) Flange connection valve: The valve body is flanged and connected to the pipe flange.

(3) Welded connection valve: The valve body has a welding groove and is welded to the pipe.

(4) Clamp connection valve: The valve body has a clamping port and is connected with the pipe clamp.

(5) ferrule connection valve: connected with the pipe with a ferrule.

(6) Matching the connecting valve: The connection form in which the valve and the two pipes are directly clamped together by bolts.

8, according to valve body material classification

(1) Metal material valve: The valve body and other parts are made of metal material. Such as cast iron valves, cast steel valves, alloy steel valves, aluminum alloy valves, lead alloy valves, etc.

(2) Non-metallic material valves: Parts such as valve bodies are made of non-metallic materials. Such as plastic valves, ceramic valves, glass steel valves and so on.

(3) Metal valve body lining valve: The shape of the valve body is metal, and the main surfaces in contact with the medium are lining, such as rubber-lined valve, plastic-lined valve, and ceramic-lined valve.