According to the use and pipe materials, the commonly used connection methods of construction pipelines are: threaded connection, flange connection, welding, groove connection (clamp connection), ferrule connection, compression connection, hot melt connection, socket connection, etc. Threaded connection is to use threaded pipe fittings to connect, and galvanized steel pipes with a pipe diameter less than or equal to 100mm should be connected with threads, which are mostly used for exposed pipes. Steel-plastic composite pipes are also generally connected with threads. Galvanized steel pipes should be connected by threads, and the surface of the galvanized layer and the exposed threaded parts that are damaged during threading should be treated with anti-corrosion; flanges or ferrule-type special pipe fittings should be used for connection, and the welds between galvanized steel pipes and flanges should be two Secondary galvanized. Pipes with larger diameters are connected by flanges. Flange connections are generally used in main road connecting valves, check valves, water meters, water pumps, etc., as well as on pipe sections that need to be disassembled and overhauled frequently. If the galvanized pipe is connected by welding or flange, secondary galvanizing or anti-corrosion should be carried out at the welding place. Welding is suitable for non-galvanized steel pipes, mostly used for concealed pipes and pipes with larger diameters, and is widely used in high-rise buildings. Copper pipes can be connected by special joints or welding. When the pipe diameter is less than 22mm, socket or sleeve welding should be used. The socket should be installed facing the flow direction of the medium. Socket welding can be used for stainless steel pipes. The groove type connector can be used for fire fighting water, air conditioning cold and hot water, water supply, rainwater and other systems with a diameter greater than or equal to 100mm galvanized steel pipe. It has simple operation, does not affect the original characteristics of the pipeline, safe construction, and good system stability. , easy maintenance, labor-saving and time-saving features. Aluminum-plastic composite pipes are generally crimped with threaded ferrules. Put the fitting nut on the end of the pipe, then put the inner core of the fitting into the end, and use a wrench to tighten the fitting and the nut. The connection of copper pipes can also be crimped with threaded ferrules. The stainless steel compression pipe fitting connection technology replaces the traditional water supply pipe connection technology such as threading, welding and gluing. It is connected with the pipeline, and the nozzle is pressed with special tools to play the role of sealing and fastening. It has the advantages of convenient installation, reliable connection and economical rationality during construction. The connection method of the PPR pipe can use a hot melter for hot melt connection. The socket connection is used for the connection of water supply and drainage cast iron pipes and fittings. There are two types of flexible connection and rigid connection. The flexible connection is sealed with a rubber ring, and the rigid connection is sealed with asbestos cement or expandable packing. In important occasions, lead sealing can be used.
