Stainless steel pipe connection methods and their respective advantages and disadvantages

- Apr 04, 2018-

There are many methods for connecting stainless steel pipe fittings. The main ones are press-fit connections, ring-pressure connections, flange connections, grooved connections, welded connections, and tapered screw connections. They are good and bad, and in the actual situation they need to find the most suitable method.
Press connection


The connection principle of this method is to use hydraulic clamps to clamp the stainless steel pipe fittings on the pipe. At the same time, the O-ring seal is used to achieve the water stop effect, thereby having a connection effect. Although this method is easy to operate, the wall of the tube is very thin, and the connection strength is as low as about one-third that of the tube, and the pipeline cannot be dismantled. The burrs of the stainless steel tube and the clearing of the flash can easily damage the apron. It is easy to leak water.
Ring pressure connection


The principle of the ring-pressure connection is to use hydraulic clamps to clamp the stainless steel pipe fittings on the pipe, and use a wide-band rubber seal ring to stop the water, so as to achieve a good connection effect. Because this method has one more pressing hole than the press type, the connection strength is slightly stronger than that of the press type. In addition, since the pressing hole is a ring type, the pipe is easy to rotate, which affects the overall sealing effect.


Flange connection


The principle of flange connection is to use a tightening bolt to connect the two connectors with a flange piece, and then seal through the flat sealing plate to achieve the corresponding connection effect. The advantage is that the connection strength is high quality and stable, and the installation is easy and detachable, but the disadvantage is that the cost of the flange piece is relatively high.


Groove connection


The principle of this method is to tighten the nut of the pipe, press the stainless steel pipe and the pipe piece with the convex ring axially, and then use the conical sealing ring to stop the water, so as to achieve the connection effect. The advantage is that it can be disassembled. The disadvantage is that during the installation process, the process of rolling the concave ring at the pipe end is increased, the cast collar is relatively expensive, and it cannot be used in a pipeline with negative pressure.


Welding connection


The connection principle of this method is to directly weld the two connectors by a hot melt process so as to achieve a connection. The advantage is that the connection strength is high, but the disadvantage is that the weld gas protection at the welding spot is difficult to meet the standard, the weld rust easily, which will reduce the service life of the pipe, and the installation quality depends to a large extent on the welding technology Level, so the quality is not stable.


Taper thread connection


The connection principle of this method is to directly tighten the stainless steel pipe fittings, and tighten the two connecting pieces with the internal and external interfaces of the conical pipe thread to achieve the sealing effect by connecting the pressure of the thread to complete the connection. Its advantages are easy to disassemble, the strength of the connection port can reach the strength of the pipe body, the installation is convenient and simple, the quality is reliable and stable, and the wall thickness of the pipe is thin, resulting in low cost. In addition, if the external thread interface is wrapped around the PTFE raw tape, it needs to be added. Force, and if you use liquid raw tape, you can basically guarantee that the interface will not leak for a long time.