Three connection methods of large-diameter spiral steel pipes

　　The most commonly used connection method for large-diameter spiral steel pipes is welding, but in some projects, threaded connections, flange connections, socket connections, groove connections, etc. are often used.

　　Welding and flange connection: Welding and flange connection are traditional spiral steel pipe connection methods, which are far from meeting the market demand in terms of safety, sealing performance, cost space, and emergency repair efficiency.

　　Scope of application: water pipeline connection, oil and gas pipeline connection, chemical pipeline connection, power pipeline connection

　　Grooved pipe fittings connection: Grooved pipe fittings connection technology, also known as clamp connection technology, has become the first technology for liquid and gas pipeline connections. Although the development time of this technology in China is later than that in foreign countries, due to its advanced technology, was quickly accepted by the domestic market. The application of grooved pipe fittings connection technology makes the complex pipeline connection process simple, fast, and convenient. The pipeline connection technology has taken a big step forward.

　　Grooved connection fittings include two broad categories of products:

　　①The pipe fittings that play the role of connection and sealing include rigid joints, flexible joints, mechanical tees, and grooved flanges;

　　② The pipe fittings that play the role of connecting transition include elbows, tees, crosses, reducers, blind plates, spiral welded pipes, etc. The grooved connection pipe fittings used for connection and sealing are mainly composed of three parts: sealing rubber ring, clamp, and locking bolt. The rubber sealing ring on the inner layer is placed on the outside of the pipe to be connected and matches the pre-rolled groove, then buckle the clamp on the outside of the rubber ring, and then fasten it with two bolts. Due to the unique sealable structural design of the rubber sealing ring and the hoop, the grooved joint has good sealing performance, and the sealing performance is enhanced correspondingly with the increase of the fluid pressure in the pipe.

　　The groove connection makes the pipe connection operation simple, which is conducive to construction safety, good system stability, convenient maintenance, labor, and time-saving and thus has good economic benefits. With the clamp connection, although the price of a single piece of the clamp is relatively high, the comprehensive benefits of the installation of the entire pipe network are higher than that of the flange connection.