Pipeline, pipe classification and common sense.
Pipeline System Overview: In order to transport liquid or gas, you must use a variety of pipelines, pipelines in addition to straight pipe with steel pipe, but also use a variety of pipe fittings: Pipe bend must be elbow, , The fork when you want to use three links, pipe joints and connectors connected to use the flange, in order to achieve the purpose of opening the transmission medium, but also with a variety of valves, in order to reduce the thermal expansion or contraction of the pipeline system, Also use expansion joints.
In addition, in the pipeline, there are various instruments and meters connected to various connectors, plug and so on.
We are accustomed to the pipe system in addition to straight pipe other parts collectively referred to as pipe fittings.
two.
Common sense of metal materials: Metal materials are the most widely used materials in our daily life and industry.
It is mainly divided into steel, iron and non-ferrous metals and other categories, of which the steel is the most widely used materials, the main component of steel is iron, the rest is artificially added alloying elements and impurities.
It is because of the different types of these alloying elements that different amounts of steel form a wide variety of steels, such as plain carbon steel, stainless steel, alloyed steels, etc. Among these added elements, carbon C plays a very important role .
2.1 Common chemical elements in steel: The majority of the various steels are iron (Fe), which usually contains the following elements (often referred to as alloying elements in steel): C (carbon) Si (Silicon) Mn (manganese) P (phosphorus) S (sulfur) and Cr (chromium) Ni (nickel) Mo (molybdenum) Ti (titanium) V (vanadium)
Under normal circumstances, where P, S as impurity components, the lower the better the quality of steel.
2.2 Classification of Steel: According to the different types of alloying elements added in steel, we can simply divide the steel into three categories: carbon steel, alloy steel, stainless steel, carbon steel, in which alloying elements are only C, Si, Mn, P, S five kinds, according to the P, S impurity level, is divided into general carbon steel (P, S generally