The pipeline classification and grading

The pipeline project is a very widely used construction technology, occupies an important position in the construction project, the type of pipeline, mainly in the transport fluid medium for the primary purpose.

Tubing and Casing, Line Pipes

For example, our daily lives can not be separated from the water supply and drainage, heating with hot water or steam, gas, etc..

Piping ships classified in several different ways, commonly Sorted by press working pressure, operating temperature, the transmission medium of the classification commonly used classification method is as follows:

Pipeline classfication

Class Name  Design Pressure P (mpa)
 vacuum piping  P<0
 low pressure piping  0<P≤1.6
 medium pressure piping  1.6<P≤10.0
 high pressure piping 10.0<P≤42.0

Under pressure in the medium, the pipeline must meet has sufficient mechanical strength and sealing performance. Pipes and piping accessories used in the pipe network as well as the connection way have to be safe and reliable under the action of pressure medium and does not leak tight.

 Class Name  Medium temperature T (℃)
 Low temperature pipes  T<-40 ℃
 Atmospheric pressure pipeline  -40 ℃<T<120 ℃
 Temperature pipeline  121 ℃<T<450 ℃
 High temperature piping  450 ℃<T

Pipe under the effect of temperature in the medium should have a stable and reliable heat resistance to withstand the medium temperature and pressure pipes must be in terms of both heat and pressure to meet the requirements of the pipe network. The interaction of medium temperature and ambient temperature, the pipeline will have a thermal deformation of the pipe to withstand thermal stress.

Pipeline grading

 Grade  operating pressure (Mpa)  operating Temperature (Mpa)
 Ⅰ  P>6.4  T>450        T>-140--45
 Ⅱ  P>4-6.4  T>350-450   T>-45--30
 Ⅲ  P>1.6-4  T>200-350   T>-30--20
 Ⅳ  P≤1.6  T>-20-200

The pipeline classification is based on two parameters of the maximum operating pressure and maximum operating temperature of the pipe network transmission medium to determine the level of the pipeline.

The pipe is coupled into the device for conveying gas, liquid or solid particles in the fluid pipe, pipe couplings and valves.

Tech & Service of Seamless pipe

Seamless pipes are extensively applied for the nuclear device, gas, petrochemical, ship building and boiler industries. Seamless pipes dominates 65% of market share in Chinese boiler industry.

How to make seamless pipe(seamless pipe process)?
Hot Piercing Workshop
Piercing process
The cross roll piercing and pilger rolling process in the size range from approx. 250 to 660 mm outside diameter.
Precision cold drawn steel tube production process
Pipe weld cracks
often follow different mechanisms can be divided into two types of thermal cracking and cold cracking.
How to calculate a steel pipe and tube theoretic weight
Calculate a steel pipe?
Pipe fittings are necessary to join together pipes, or to change the direction of an existing pipe.
Pipe beveling
Pipe beveling is the process where an angle is formed between the edge of the end of a pipe or tube and a plane perpendicular to the surface.
Steel pipe cutting machine
Pipe cutting
Cutting tools have a grinding wheel piece cutting machine (also known as toothless saw), hand saw, cutter and other hand tools.
Packing the steel pipes
There are probably hundreds of different methods for packing a pipe, and most of them have merit, but there are two principles that are vital for any method.


Our team are highly trained and experienced in servicing and producing all types of steel supplies. Whether you've got a large construction project, or need parts for industrial machinery, our team of steel fabrication consultants will ensure that your project is provided with the parts you need, when you need them.

Link exchange

Copyright © 2011 Sunny Steel Enterprise Ltd.  All Rights Reserved ICP No.:08010763