What are the connection methods for seamless steel pipes

1. Compression type: Insert the pipe into the nozzle of the pipe fitting, fasten it with a nut, and use the screw force to compress the sleeve at the nozzle through the sealing ring, which acts as a seal and completes the connection of the pipe.
2. Welding type: The end of the pipe is grooved, and the pipe is ring-welded by manual or automatic welding.
3. Flange type: The flange and the pipe are welded by circular argon arc welding, and fastened with quick clamps or bolts so that the gasket between the flanges acts as a seal to complete the pipe connection.
4. Clamping type: Insert the pipe into the pipe fitting and use a special installation tool to clamp the pipe wall into a hexagonal shape, and the internal sealing ring also changes into a hexagonal shape.
5. Taper thread type: The external thread and the piping are subjected to circular argon arc welding, and the internal thread pipe fittings are connected with a tapered thread for sealing to complete the piping connection.

Replenish:
1. The production process of seamless steel pipe can be divided into cold drawing and hot rolling. The production process of cold-rolling seamless steel pipe is generally more complicated than hot-rolling. After the sizing test, if there is no response crack on the surface, the round pipe will be cut by a cutting machine and cut into a blank of about one meter in length.
2. Enter the annealing process. Annealing should be pickled with an acidic liquid. When pickling, pay attention to whether there is a large amount of foaming on the surface. If there is a large amount of foaming, it means that the quality of the steel pipe cannot meet the corresponding standards.
3. The delivery state of hot-rolled seamless steel pipes is generally in the hot-rolled state after heat treatment. After passing the quality inspection, the hot-rolled seamless steel pipe must be strictly hand-selected by the staff. After the quality inspection, the surface must be oiled, followed by multiple cold-drawing experiments, and the perforation experiment must be carried out after the hot-rolling treatment. , if the diameter of the perforation is too large, it needs to be straightened and corrected.
4. The outer diameter of the hot-rolled seamless pipe is generally greater than 32mm, and the wall thickness is 2.5-200mm. The outer diameter of cold-rolled seamless steel pipe can reach 6mm, and the wall thickness can reach 0.25mm. The outer diameter of a thin-walled pipe can reach 5mm, and the wall thickness is less than 0.25mm. , cold rolling has higher dimensional accuracy than hot rolling.
5. Generally used seamless steel pipes are made of high-quality carbon steel such as 10, 20, 30, 35, 45, 16Mn, 5MnV, and other low-alloy structural steels or 40Cr, 30CrMnSi, 45Mn2, 40MnB and other combined steels that are hot-rolled or cold-rolled. of. Seamless pipes made of 10 and 20-grade low-carbon steel are mainly used for fluid transportation pipelines.
6. There are three ways to connect the pipe thread: cylindrical internal thread inserted into cylindrical external thread, cylindrical internal thread inserted into conical external thread, and conical internal thread inserted into conical external thread. Among them, the latter two methods are more closely connected and are the most commonly used connection methods.
(1), flange flange connection. Flanged loose sleeve flanges are generally used for pipes of similar materials such as copper pipes, lead pipes, and plastic pipes. When flanging, different operating methods are selected according to different materials. The flanging is required to be flat, without cracks and wrinkles.
(2) Threaded flange connection, using flanges with internal threads to connect with steel pipes with external threads. This flange is mostly made of cast iron and can be used for the connection of low-pressure pipelines.
(3) Welded flange connection. The flange and the steel pipe are welded. This flange connection is widely used. The welding method is as follows: select a pair of flanges and install them on the two connected pipe ends respectively. If some equipment has flanges, choose flanges of the same specification and place them on the spot welding point first. Correct the verticality, and finally weld the flange and the pipe firmly.