Large diameter spiral welded steel pipe is a steel pipe used to transport liquids or gases and support structures. It is characterized by a large diameter, usually greater than 24 inches (609.6 mm). This type of pipe is usually manufactured through a spiral welding process, hence the name spiral welded steel pipe.

321 has one more trace element of titanium than 304. The role of titanium in stainless steel is very obvious, which can make stainless steel pipes have better corrosion resistance and high temperature resistance.

3PE anti-corrosion steel pipe refers to a 3-layer structure polyolefin coating (MAPEC) external anti-corrosion steel pipe.

Directly buried insulated steel pipes are composed of three layers: inner steel pipe, polyurethane foam layer and outer protective pipe.

There are three connection methods for spiral steel pipes: flange connection, welded connection and threaded connection.

Welded steel pipes and seamless steel pipes are both commonly used pipe materials, and they have different characteristics in use.