Analysis of optional connection methods for stainless steel pipes

Stainless steel pipe compression connection
Domestic compression pipe fittings are the same as the compression pipe fittings above. They are a connection method in which the pipe is inserted into the socket of the pipe fitting and tightened with a nut to compress the sealing ring to act as a seal. It is similar to the traditional threaded connection of pipelines, but the difference is that on the basis of the threaded connection, a sealing ring is added for sealing. In addition, the threads need to be processed in advance and welded to the pipe fitting body. Special tools for piping are bulged, and the entire pipe fitting is also Includes prefabricated nuts. Its advantages are simple installation, detachability, and convenient maintenance. The surface-mounted pipes are bright and luxurious and can be used as jewelry. But the disadvantage is the high cost.
Pressure type and snap ring type
The clamping type is a connection method in which after the pipe is inserted into the socket of the pipe fitting, a special tool is used to compress the pipe opening to achieve sealing and tightening. The snap ring type and the compression type are similar. Suitable for exposed and concealed pipes.
Both the clamping type and the snap ring type use special calipers to compress the pipes and fittings to receive radial force to achieve sealing and tightening effects. The main difference between the clamping type and the snap ring type is that the former can be pressed once, while the latter requires the pipes and fittings to be axially rotated 30°-90° before being pressed a second time.
The advantage of these two methods is that they are easy to install, but the disadvantage is that the service life of the rubber ring is far less than that of the stainless steel pipe. Once it leaks, it is troublesome to repair, and the larger the diameter of the pipe, the more difficult it is to press it.
telescopic flexible
The telescopic flexible type is a connection method in which stainless steel pipe piping is inserted into the socket of the pipe fitting, the inner nut is tightened, and the sealing ring is pressurized through the extrusion ring to act as a seal. It has axial telescopicity and radial flexibility, and has strong earthquake resistance and foundation sinking capabilities, but the cost is relatively high.
Welded
The welded connections of thin-walled stainless steel pipes include socket TIG welding and butt TIG welding. Among them, the socket argon arc welding type connection is a connection method in which the pipe is inserted into the socket of the pipe fitting and welded by tungsten argon arc welding to form a unified body, commonly known as "jointless connection".
Socket-type and welded-type pipe connections are common connection methods for pipelines. The innovative socket-type argon arc welded pipe fittings and connection methods draw on the advantages of traditional socket-type pipe connections and welded-type pipe connections, and combine them organically. The combination is suitable for the good welding performance of stainless steel.
The pipe fitting socket and pipe body are TIG welded, and the socket is designed with a special extended edge, which is used instead of welding wire during installation and welding. The wall thickness of the entire pipe fitting is generally not less than that of the same diameter pipe. Another type of socket-welded pipe fittings, the socket is processed by expanding, which has a simple process and low cost. Welding wire and other auxiliary materials are required during installation and welding.

The second is butt argon arc welding connection, which is a connection method in which pipes and pipe fittings are butted or pipes are butted, and TIG welding is used to form a "jointless connection". The welding process requires welding wire or electrode.

flange type
The flange connections of thin-walled stainless steel pipes mainly include flat flanges, union flanges and clamp flanges. Stainless steel pipe flat flange is a traditional flange similar to carbon steel flange. The sealing gasket between the two flanges should depend on the transmission medium. The size and quantity of fasteners are selected according to the working pressure and pipe diameter.
The second is the union flange. A stainless steel sealing ring is sandwiched between the two stainless steel pipe flat flanges. The ring is lined with a sealing ring on both sides and is also fastened with fasteners. The difference is that the mating surface of the union flange has a countersunk hole to inlaid with a stainless steel sealing ring.
Clamp flange, the stainless steel clamp and the flange piece are matched through a tapered groove. There is a sealing gasket between the two flange pieces and they are tightened by set screws.
union
The so-called union is when the two pipe ports are flanged at 90°, and then O-rings, metal sealing rings and washers are placed sequentially between the butt planes. The stainless steel pipe fittings are sealed through the meshing force of the inner and outer nuts inserted in advance. connection method. It is mainly suitable for surface-mounted pipes and is a detachable connection.
Grooved
After the grooves are machined at the ends of the two stainless steel pipes, the clamps are inserted into the grooves during docking, and the bolts on the clamps are tightened with a wrench to achieve a sealing and tightening connection. The connection method of this kind of stainless steel pipe is detachable. The clamp of the grooved pipe fitting is made of ductile iron and is divided into two types: rigid and flexible.
Adhesive type
This connection method is formed by first reducing the diameter of the pipe end into a tapered shape, and then bonding the pipe fitting socket with adhesive.
Adhesives include anaerobic sealing adhesives, etc.
In general, the most commonly used connection methods for thin-walled stainless steel pipes include compression type, welding type, etc.