The identification and model of the valve, a must-see for beginners!

　　Beginners often mistakenly believe that a faucet is a valve. In fact, a faucet strictly belongs to the bathroom series. Valves are divided into gate valves, shut-off valves, butterfly valves, high-pressure valves, low-pressure valves, fluorine-lined valves, safety valves, pressure relief valves, anti-corrosion valves, filters, check valves, pressure reducing valves, flow valves, ceramic valves, medium pressure valves, high temperature valves, low temperature valves, etc.
　　1. Classification
　　▍ By Power Source
　　1. Automatic Valves
　　Valves that operate relying on the medium's own power, such as check valves, pressure reducing valves, drain valves, safety valves, etc.
　　2. Driven Valves
　　Valves that are manipulated by external forces such as manual, electric, hydraulic, or pneumatic power, such as shut-off valves, throttle valves, gate valves, butterfly valves, ball valves, and plug valves.
　　▍ By Structural Characteristics
　　1. Gate Type: The closing element moves along the centerline of the valve seat.
　　2. Slide Gate Type: The closing element moves along a line perpendicular to the valve seat.
　　3. Plug Type: The closing element is a plunger or ball that rotates around its own centerline.
　　4. Rotating Type: The closing element rotates around an axis outside the valve seat.
　　5. Disc Type: The closing element is a disc that rotates around an axis inside the valve seat.
　　6. Sliding Valve Type: The closing element slides in a direction perpendicular to the passage.
　　▍ By Purpose
　　1. On/Off Use: Used to cut off or connect the medium in the pipeline, such as shut-off valves, gate valves, ball valves, and plug valves.
　　2. Regulation Use: Used to regulate the pressure or flow of the medium, such as pressure reducing valves and regulating valves.
　　3. Distribution Use: Used to change the flow direction of the medium, serving a distribution function, such as three-way plugs and three-way shut-off valves.
　　4. Check Use: Used to prevent backflow of the medium, such as check valves.
　　5. Safety Use: Discharges excess medium when the pressure exceeds a specified value to ensure equipment safety, such as safety valves and emergency valves.
　　6. Gas Drainage Use: Retains gas and discharges condensate, such as drain valves.
　　▍ By Operation Method
　　1. Manual Valves: Valves operated by human power using handwheels, handles, levers, chain wheels, gears, worm gears, etc.
　　2. Electric Valves: Valves operated using electric power.
　　3. Pneumatic Valves: Valves operated using compressed air.
　　4. Hydraulic Valves: Valves operated using liquids such as water or oil to transmit external force.
　　▍ By Pressure
　　1. Vacuum Valves: Valves with absolute pressure less than 1 kg/cm².
　　2. Low Pressure Valves: Valves with nominal pressure less than 16 kg/cm².
　　3. Medium Pressure Valves: Valves with nominal pressure between 25-64 kg/cm².
　　4. High Pressure Valves: Valves with nominal pressure between 100-800 kg/cm².
　　5. Ultra High Pressure: Valves with nominal pressure reaching or exceeding 1000 kg/cm².
　　▍ By Medium Temperature
　　1. Ordinary Valves: Valves suitable for medium working temperatures from -40 to 450℃.
　　2. High Temperature Valves: Valves suitable for medium working temperatures from 450 to 600℃.
　　3. Heat Resistant Valves: Valves suitable for medium working temperatures above 600℃.
　　4. Low Temperature Valves: Valves suitable for medium working temperatures from -40 to -70℃.
　　5. Deep Cold Valves: Valves suitable for medium working temperatures from -70 to -196℃.
　　6. Ultra Low Temperature Valves: Valves suitable for medium working temperatures below -196℃.
　　▍ By Nominal Diameter
　　1. Small Diameter Valves: Valves with nominal diameter less than 40 mm.
　　2. Medium Diameter Valves: Valves with nominal diameter between 50 to 300 mm.
　　3. Large Diameter Valves: Valves with nominal diameter between 350 to 1200 mm.
　　4. Extra Large Diameter Valves: Valves with nominal diameter greater than 1400 mm.
　　The above classifications are not absolute and can also be categorized from other perspectives, but mastering these basic classifications is very beneficial for understanding the wide variety of valves.