Control valves are core control components in pipeline systems. Their core function is to precisely regulate key parameters of the medium (liquid, gas, steam, etc.) within the pipeline by changing the flow area between the valve core and seat, thus meeting the process requirements and stable operation needs of industrial production, energy supply, water treatment, and other scenarios.

1. Classification by Structural Form 2. Classification by function and application scenario 3. Classification by material 4. Classification by connection method 5. Classification by special working conditions.

1. Pressure Regulation and Stabilization.2. Protecting Equipment and System Safety.3. Energy Saving and Optimized Operation.4. Adapt to Different Operating Conditions.5. Flow Control Assistance.

Metal materials are the core choice for valve bodies due to their high strength and good pressure resistance. According to the material properties, they can be divided into cast iron, cast steel, stainless steel, non-ferrous metals and corrosion-resistant alloys.

The key reason a valve fails to open after being closed for an extended period is that, due to the media and environmental influences, the valve's internal components undergo physical or chemical changes during prolonged static operation. This can cause moving parts (such as the valve stem, gate, and ball) to become stuck or locked, preventing them from operating normally.

Selecting valves for corrosive media like strong acids and alkalis is a critical and highly specialized issue. Improper selection can lead to rapid valve failure and media leakage, resulting in safety incidents, environmental pollution, and production interruptions.