According to the purpose and pipe material, the commonly used connection methods of construction
steel pipelines are threaded connection, flange connection, welding, groove connection (clamp connection), ferrule connection, compression connection, hot melt connection, socket connection, etc.
1. Threaded connection: Threaded connection is to use threaded pipe fittings to connect. Galvanized steel pipes with a pipe diameter less than or equal to 100mm are suitable for threaded connections and are mostly used for surface-mounted pipes. Steel-plastic composite pipes are generally also threaded. The galvanized steel pipe shall be connected by threads, and the surface of the galvanized layer and the exposed thread parts damaged during the threading shall be treated with anticorrosion; flanges or ferrule-type special pipe fittings shall be used for connection, and the welding place between the galvanized steel pipe and the flange shall be two Secondary galvanizing.
2. Flange connection: Pipes with larger diameters are connected by flanges. Flange connections are generally used in main roads to connect valves, check valves, water meters, water pumps, etc., as well as pipe sections that require frequent disassembly and maintenance. If the galvanized pipe is connected by welding or flange, the welding place should be galvanized twice or anti-corrosion.
3. Welding: Welding is suitable for non-galvanized steel pipes, mostly used for concealed pipes and large-diameter pipes, and is widely used in high-rise buildings. Copper pipe connections can use special joints or welding. When the pipe diameter is less than 22mm, it should be welded by a socket or sleeve. Stainless steel pipes can be socket welded.
4. Groove connection (clamp connection): Groove connection can be used for galvanized steel pipes with a diameter greater than or equal to 100mm in fire water, air-conditioning hot and cold water, water supply, rainwater, and other systems. It is easy to operate and does not affect the pipeline. Original features, safe construction, good system stability, convenient maintenance, saving labor and time, etc.
5. Ferrule connection: Aluminum-plastic composite pipes are generally crimped with threaded ferrules. Put the fitting nut on the end of the pipe, then insert the inner core of the fitting into the end, and tighten the fitting and the nut with a wrench. The connection of copper pipes can also be crimped with threaded ferrules.
6. Compression connection: stainless steel compression pipe fittings connection technology replaces traditional water supply pipeline connection technologies such as thread, welding, and glue. It has the characteristics of protecting water quality and sanitation, strong corrosion resistance, and long service life. The socket pipe fitting of the sealing ring is connected to the pipeline, and the pipe mouth is pressed with a special tool to seal and fasten it. It has the advantages of convenient installation, reliable connection, and economical and reasonable during construction.
7. Hot-melt connection: The connection method of the PPR pipe is to use a hot-melt machine for a hot-melt connection.
8. Socket connection: the connection of steel pipe fittings. There are two types of flexible connections and rigid connections. Flexible connections are sealed with rubber rings, rigid connections are sealed with asbestos cement or expansive packing, and lead seals can be used for important occasions.
