There are many ways to connect seamless tubes, the most common are the following:

1. Butt welding connection

Butt welding connection is one of the most commonly used seamless tube connection methods at present. Butt welding can be divided into manual butt welding and automatic butt welding. Manual butt welding is suitable for the connection of seamless steel tubes with small diameter and low pressure, while automatic butt welding is suitable for the connection of seamless steel tubes with large diameter and high pressure. The butt welding connection has the advantages of simple structure and good reliability, and is suitable for industries such as chemical industry and electric power.

2. Threaded connection
Threaded connection is a common seamless tube connection method. It can be divided into two ways of internal thread connection and external thread connection, suitable for delivery systems under low pressure, such as tap water, natural gas, etc. The screw connection is simple and easy to use, and the disassembly and maintenance are convenient.

3. Flange connection
Flange connection is a common high-pressure pipeline connection method, which is suitable for high-pressure, high-temperature, large-diameter seamless steel tube connection. There are many types of flanges, including flat welding flanges, butt welding flanges, threaded flanges, etc. Different types of flanges can be selected to meet different engineering needs. Flange connection has the advantages of reliable connection and good sealing, but it is difficult to install and maintain.

4. Plug-in connection
The plug-in connection is a simple and convenient seamless tube connection method. It can be divided into two methods: cap plug-in connection and sleeve plug-in connection. It is suitable for the connection of seamless steel tubes with small and medium diameters and low pressure. The plug-in connection has the advantages of simplicity, convenience, and no need for special equipment.

In short, the selection of seamless tube connection method should be comprehensively considered according to engineering requirements, pipeline type, pressure level, use environment and safety requirements, etc., and the selection of a suitable connection method can ensure the normal operation and service life of the pipeline.