Gas valves have a wide range of uses, a wide variety, and a variety of classification methods. In general, it can be divided into two categories:
The first type of automatic valve: is a valve that operates by itself depending on the ability of the gas itself. Such as check valve, regulating valve, pressure reducing valve, etc.
The second type of actuated valve: is the valve that operates the action by means of manual, electric, and pneumatic. Such as gate valve, globe valve, throttle valve, butterfly valve, ball valve, plug valve, etc.

In addition, there are several ways to classify valves:
According to the structural characteristics, it can be divided according to the direction of movement of the closing part relative to the valve seat:
1. Gate shape: The closing member moves along the center of the valve seat.
2. Gate shape: The closing piece moves along the center of the vertical seat.
3. Plug and Ball: The closure is a plunger or ball that rotates around its own centerline.
4. Swing: The closure member rotates around an axis outside the seat.
5. Disc: The disc of the closure that rotates around an axis in the seat.
6. Spool type: The closing member slides in the direction perpendicular to the channel.

According to the type of structure, there are mainly:
Plug valves, gate valves, globe valves, ball valves—are used to open or close the flow of gas in pipes. Check valve (including foot valve) - used to automatically prevent the backflow of gas in the pipeline.
Throttle valve - used to regulate the flow of gas in the pipeline.
Pressure-reducing valve - used to automatically reduce the gas pressure in pipelines and equipment. When the gas passes through the gap of the valve disc, resistance is generated and pressure loss is caused to achieve the purpose of decompression.

The use, according to the different uses of the valve, can be divided into:
1. For breaking: used to connect or cut off pipeline gas, such as globe valve, gate valve, ball valve, butterfly valve, etc.
2. Check use: used to prevent the backflow of gas, such as a check valve.
3. Adjustment: used to adjust the pressure and flow of gas, such as regulating valve, and pressure reducing valve.
4. Distribution: used to change the flow direction of gas and distribute gas, such as three-way cock, distribution valve, slide valve, etc.

The driving mode, can be divided into different driving modes:
1. Manual: With the help of a handwheel, handle, lever or sprocket, etc., it is driven by human power. When transmitting a large torque, it is equipped with a reduction device such as a worm gear and a gear.
2. Electric: driven by a motor or other electrical device.
3. Pneumatic; powered by compressed air.

According to the connection method with the pipeline, it can be divided according to the connection method between the valve and the pipeline;
1. Flanged valve: the valve body is flanged, and the valve is flanged to the pipeline.
2. Threaded valve: the valve body has an internal thread or external thread, and the valve is connected to the pipeline by a thread.
3. Welded connection valve: The valve body has a welded joint and is connected to the pipeline by welding.
4. Clamp-connected valve: a valve with a clamp port on the valve body and a clamp-clamp connection with the pipeline.
5. Card sleeve connection valve: a valve that uses a card sleeve to connect to the pipeline.