(1) Block valve is mainly used to block or connect the medium flow. Including gate valves, globe valves, diaphragm valves, ball valves, plug valves, butterfly valves, plunger valves, spherical plug valves, needle instrument valves, etc.

(2) The regulating valve is mainly used to regulate the flow and pressure of the medium. Including regulating valve, throttle valve, pressure reducing valve, etc.

(3) The check valve is used to prevent the medium from flowing back. Include check valves of various structures.

(4) The diverter valve is used to separate, distribute or mix media. Include distribution valves and traps of various structures.

(5) The safety valve is used for safety protection when the medium is overpressure. Include various types of safety valves.

1.2 classified by main parameters

1.2. 1 classified by pressure

(1) A valve whose working pressure is lower than the standard atmospheric pressure.

(2) Low pressure valve with nominal pressure PN≤ 1.6 MPa.

(3) Valves with nominal pressure PN of 2.5 MPa, 4.0 MPa and 6.4 MPa.

(4) valves with nominal pressure PN of 10.0~80.0 MPa.

(5) Ultra-high pressure valve with nominal pressure PN≥ 100 MPa.

1.2.2 classified by medium temperature

(1) high temperature valve is used for valves with medium working temperature t > 450℃.

(2) The medium temperature valve is used for valves with medium working temperature of 120℃.

(3) Normal temperature valves are used for valves with medium working temperature of -40℃ ≤ t ≤ 120℃.

(4) Low-temperature valves are used for valves with medium working temperature of-100℃ ≤ t ≤ -40℃.

(5) Ultra-low temperature valves are used for valves with medium working temperature T.

1.2.3 Classification by valve body material

(1) Non-metallic valves: such as ceramic valves, FRP valves, plastic valves, etc.

(2) Metal valves: such as copper alloy valves, aluminum alloy valves, lead alloy valves, Qin alloy valves, Monel alloy valves, cast iron valves, carbon steel valves, cast steel valves, low alloy steel valves and high alloy steel valves.

(3) Metal body lined valves: such as lead lined valves, plastic lined valves and enamel lined valves.

The valve structure diagram can refer to various valve standards, such as: butterfly valve: GB/T12238-2008; Check valve: JB/T8937-20 10 ...