Stainless steel pipe is a hollow elongated round steel material, which is widely used in petroleum, chemical, medical, food, light industry, mechanical instrumentation and other industrial pipelines and mechanical structural components. In addition, when the bending and torsional strength are the same, the weight is lighter, so it is also widely used in the manufacture of mechanical parts and engineering structures. It is also commonly used as furniture and kitchen utensils.

The method of using acid solution to remove scale and rust on the surface of seamless steel pipes is called seamless pipe pickling, which is a method of cleaning the surface of steel pipes.

The welded pipe is a steel pipe made of steel plate or strip steel after being crimped and welded, generally with a length of 6 meters. The production process of welded steel pipe is simple, the production efficiency is high, there are many varieties and specifications, and the investment in equipment is small, but the general strength is lower than that of seamless steel pipe. Welded steel pipes are divided into straight seam welded pipes and spiral welded pipes (SSAW steel pipe) according to the form of welds. Classification by production method: process classification - arc welded pipe, electric resistance welded pipe (ERW pipe), (high frequency, low frequency) gas welded pipe, furnace welded pipe.

The hot-dip galvanizing of seamless steel pipes is to pickle the steel pipes first, in order to remove the iron oxide on the surface of the steel pipes. After pickling, it is cleaned in an ammonium chloride or zinc chloride aqueous solution or a mixed aqueous solution of ammonium chloride and zinc chloride, and then sent to a hot-dip coating tank. Hot-dip galvanized seamless pipe has the advantages of uniform coating, strong adhesion and long service life.

A pressure pipe is a tubular device used to transport gas or liquid under a certain pressure. Its scope is stipulated as the gas, liquefied gas, steam medium with the maximum working pressure greater than or equal to 0.1MPa, or the liquid medium with the highest working temperature higher than or equal to the standard boiling point, which is flammable, explosive, toxic or corrosive,and the pipe with nominal diameter greater than 25mm.

Seamless steel pipe refers to a steel pipe that is made of a single piece of metal and has no seams on the surface. According to the production method, seamless tubes are divided into hot-rolled tubes, cold-rolled tubes, cold drawn seamless tubing, extruded tubes, jacked tubes, etc. The piercing methods of seamless pipe blanks include pressure piercing, push rolling piercing and skew rolling piercing.