Lianggong Valve mainly sells the following types of valves:

1. 球阀：球阀由球体和阀座构成，通过旋转球体来控制流体的开关。球阀具有结构简单、密封可靠、操作灵活等特点，广泛应用于石油、化工、天然气、水处理等行业。

1. Ball valve: The ball valve is composed of a ball and a valve seat, which controls the fluid switch by rotating the ball. Ball valves have the characteristics of simple structure, reliable sealing, and flexible operation, and are widely used in industries such as petroleum, chemical, natural gas, and water treatment.

2. 闸阀：闸阀通过提升或降下闸板来控制流体的通断。闸阀具有启闭快、流阻小、密封可靠等特点，适用于管道中需要频繁启闭或对流阻要求较低的场合。

2. Gate valve: The gate valve controls the flow of fluid by lifting or lowering the gate plate. Gate valves have the characteristics of fast opening and closing, small flow resistance, and reliable sealing, making them suitable for situations where frequent opening and closing or low flow resistance requirements are required in pipelines.

3. 截止阀：截止阀通过升降阀芯来控制流体的通断。截止阀具有密封性能好、流阻小、启闭力矩小等特点，在一般工况下都能满足要求，被广泛应用于各个行业。

3. Stop valve: The stop valve controls the flow of fluid by lifting and lowering the valve core. Globe valves have the characteristics of good sealing performance, small flow resistance, and small opening and closing torque, which can meet the requirements under general working conditions and are widely used in various industries.

4. 蝶阀：蝶阀由阀体、阀杆和蝶板组成，通过旋转蝶板来控制流体的通断。蝶阀具有体积小、重量轻、启闭迅速等特点，广泛应用于给排水、空调、暖通等系统中。

4. Butterfly valve: A butterfly valve is composed of a valve body, valve stem, and butterfly plate, which is rotated to control the flow of fluid. Butterfly valves have the characteristics of small size, light weight, and quick opening and closing, and are widely used in systems such as water supply and drainage, air conditioning, and HVAC.

5. 止回阀：止回阀用于防止介质倒流，具有自动封闭、启闭迅速等特点。止回阀广泛应用于石油、化工、电力、冶金等行业中，保护管道和设备的运行。

5. Check valve: Check valve is used to prevent medium backflow and has the characteristics of automatic sealing and rapid opening and closing. Check valves are widely used in industries such as petroleum, chemical, power, and metallurgy to protect the safe operation of pipelines and equipment.

除了以上几种常见的阀门，良工阀门还销售其他类型的阀门，如调节阀、阀、排气阀等，以满足不同行业的需求。

In addition to the common valves mentioned above, Lianggong Valve also sells other types of valves, such as regulating valves, safety valves, exhaust valves, etc., to meet the needs of different industries.