Threaded double coupling is an accessory used for pipe connection. It is usually formed by die-forging blanks of round steel or steel ingots, and then machined into shape by lathe. The connection form of the threaded double-port pipe clamp is a threaded connection, which can be connected to pipes or other pipe fittings through threads. The main manufacturing standards of this type of pipe clamp include ASME B16.11, GB/T7306, 12716, 14383, MSS SP-79, 83, 95, 97JIS B0203, B2316, etc. The varieties of threaded double-joint pipe clamps include equal-diameter and different-diameter pipe clamps, and the double-joint pipe clamps of different diameters are also divided into concentric and eccentric. They can be widely used in pipes of different diameters,including single-way, three-way, four-way, etc., and can also be used in water meters and valves.