What are the precautions for connecting stainless steel square pipes

First, how to overlap square steel pipes

Square steel pipes are widely used, including structural square steel pipes, decorative square steel pipes, building square steel pipes, mechanical square steel pipes, etc. When used, it is usually necessary to overlap multiple square steel pipes together, so how to connect square steel pipes?

1. Compression type: insert the square steel pipe into the pipe mouth of the steel pipe fitting, tighten it with a nut, and use the spiral force to compress the sleeve of the pipe mouth through the sealing ring to seal and complete the square steel pipe connection. Scope of application: DN (nominal diameter) ≤ 150mm, can be installed openly or concealed.

2. Welding type: perform annular argon arc welding on the usual socket-type pipe fittings and matching, which plays a sealing role and completes the matching connection. Scope of application: Pipes in public buildings and large buildings, DN is 15mm-100mm, DN greater than 100mm is mostly conventional butt welding; indoors can be installed openly or concealed, and outdoors buried.

3. Heat shrink pipe fittings: When connecting square steel pipes, on-site welding can be used. Since the welding points cannot be handled on-site, heat shrink fittings are used for supplementary sealing. A rubber welding sleeve is put on the welding point of the pipe, and then a special cross-linked polyethylene sleeve is put on the outer sleeve. It shrinks under the action of heat to achieve shrinkage sealing. Applicable scope: Pipes with DN below 400mm.

4. Cone thread type: The external thread sleeve and the matching are subjected to annular argon arc welding, and the internal thread pipe fittings are connected with a cone pattern to seal and complete the matching connection. Applicable scope: DN is 65mm-100mm, and the pipelines of public buildings and large buildings can be used in harsh environments such as foundation sinking, high temperature, and high pressure.

5. Limit compression type: The square steel pipe adopts a flanging or port welding ring, and the connection method is a flexible or semi-flexible connection. After the rubber sealing ring is limited and sealed by 20%-30%, it enters the metal sealing groove, and a limit seal is used to protect the sealing element. The joint can be made of copper or carbon steel. Applicable scope: DN is below 400mm, suitable for harsh environments such as foundation sinking, various high temperatures, and high pressures.

6. Quick-connect flange type: perform annular argon arc welding on the flange and the matching parts, use quick clamps to compress the sealing gasket between the flanges, play a sealing role, and complete the matching connection. The applicable range is DN 15mm-100mm, public buildings, and large buildings.

7. Flexible quick-connect flange: turn the traditional flange into a flexible flange, the square steel pipe port is flanged or welded, the ring mouth is embedded in the groove, and the sealing rubber part is placed in the groove. The limited compression method is used to protect the sealing element. The applicable range is DN below 400mm, which can be used as a buried pipe.

8. Pressing type: insert the square steel pipe into the steel pipe fitting, the two ends of the pipe fitting are protruding U-shaped grooves, with built-in sealing rings, and the socket part is pressed by a special pipe fitting tool for connection. Applicable range: DN ≤ 100mm, can be installed openly or concealed.

Second, what are the precautions for connecting stainless steel square pipes?

1. Whether it is a square steel pipe or a rectangular steel pipe, it should be supplied by the supplier in a unified manner. Square and rectangular pipes of different grades and materials should not be connected.

2. When connecting square steel pipes with threaded valves, nozzles, water meters, and other accessories, do not thread the square steel pipes, but use threaded fittings such as conversion joints for transition.

3. When underground connection is required, pay attention that square steel pipes should not be in direct contact with cement, cement mortar, and concrete. Plastic-coated thin-walled welded pipes should be used or anti-corrosion tape should be wrapped around the outer wall of the pipe.

4. When connecting square steel pipes, pay attention to avoid sharp objects colliding with square steel pipes. When using seals for connection, pay attention to avoid oil or other dirt from contaminating the seals.