Material selection and standards for steel pipes in power plants

Classification and use of steel pipes in power plants:

Steel pipes in power plants are mainly divided into two types: thermal pipes and condensing pipes. Thermal pipes are mainly used to transport heating media (such as steam or hot water), while condensing pipes are mainly used to recover and condense heat generated during the condensation process.

Material selection for steel pipes in power plants:

1. Carbon steel pipe

Carbon steel pipe (CS pipe) is one of the most commonly used pipes in power pipelines. It has good strength and rigidity and can withstand large internal and external pressures. Carbon steel is mainly composed of carbon and iron, with high strength, wear resistance and low cost. However, due to its poor corrosion resistance, it is easy to rust in a humid or corrosive environment, so corresponding anti-corrosion measures need to be taken. In the use scenario of power plants, it is mainly used for low-pressure, normal temperature condensing pipes.

2. Alloy steel pipe
Alloy steel pipe is a steel pipe containing multiple elements. One or more alloy elements can be added to carbon steel according to actual use requirements to improve the strength, corrosion resistance and wear resistance of the steel pipe, making alloy steel widely used in the field of power transmission. In power plants, alloy steel pipes (such as chromium-molybdenum steel and nickel-chromium steel) are mainly used for thermal pipelines and condensing pipelines that are subject to corrosion under high temperature and high pressure environments. Commonly used alloy elements include chromium, molybdenum, tungsten, manganese, nickel, etc.

3. Stainless steel pipe
Stainless steel is a material with excellent corrosion resistance and is widely used in power pipelines. It can resist corrosion from a variety of media such as atmosphere, water, acid, and alkali, ensuring the long-term stable operation of power pipelines in harsh environments. In addition, stainless steel also has good wear resistance and thermal conductivity, which can improve the efficiency of power transmission. However, the price of stainless steel pipes is relatively high, which increases the cost of power pipelines.

4. Other materials
According to the actual use needs of power plants, some special steel pipes are also selected, such as titanium alloy pipes, copper pipes, etc., but these steel pipes usually have higher costs and production difficulties in use.

Specific standards and requirements for material selection

a. Strength and pressure resistance: alloy steel pipes are the preferred material for high temperature and high pressure environments due to their high strength and pressure resistance.
‌b. Corrosion resistance: alloy steel pipes significantly improve corrosion resistance by adding elements such as chromium and molybdenum, and are suitable for corrosive environments.
‌c. Cost and production difficulty: special materials such as stainless steel pipes, titanium alloy pipes, copper pipes, etc., although they have excellent performance, are expensive and difficult to produce, and are usually used in specific demand occasions.

In power plants, the material selection of steel pipes needs to take into account specific usage scenarios and environments, but most power plants mainly use alloy steel pipes that can withstand corrosion in high temperature and high pressure environments. With the continuous advancement of science and technology and the continuous improvement of production processes, the types and properties of steel pipe materials will continue to be updated, providing better protection for the development and operation of power plants.

Are seamless pipes or welded pipes commonly used in power plants?

The type of pipes used in power plants depends on the specific application scenarios and working conditions. Both seamless pipes and welded pipes are widely used. The following are common situations:

1. Seamless pipe
Application scenario: high pressure and high temperature environment, such as main steam pipe, reheat steam pipe, high pressure water supply pipe, etc.
Advantages: high strength, high pressure and high temperature resistance, no welds, high safety.
Material: usually carbon steel, alloy steel or stainless steel.

2. Welded pipe
Application scenario: low pressure and low temperature environment, such as cooling water system, low pressure water supply pipe, circulating water pipe, etc.
Advantages: low cost, simple manufacturing process, suitable for low pressure and low temperature conditions.
Material: usually carbon steel or stainless steel.

3. Other types of pipes
Application scenario: special needs, such as corrosion resistance, wear resistance, etc.
Material: stainless steel, alloy steel, etc.

In summary:
Seamless pipe: mainly used in key parts of high pressure and high temperature.
Welded pipe: mainly used in auxiliary systems of low pressure and low temperature.
Therefore, both seamless pipes and welded pipes are used in power plants, and the specific choice depends on working conditions and needs.

Implementation standards for power steel pipes:

Power carbon steel pipes play a vital role in the power industry, and understanding their implementation standards is the key to ensuring the safe operation of pipeline systems. The following is a detailed interpretation of the implementation standards for power carbon steel pipes.

1. Manufacturing standards
The manufacture of electric carbon steel pipes must strictly comply with relevant standards. First, the selection of steel must comply with national regulations to ensure that it has good mechanical properties and corrosion resistance. Secondly, during the manufacturing process, the dimensional accuracy and surface quality of the steel pipe should be strictly controlled to ensure its stability and durability during use.

2. Quality control
Quality control is an important link in the implementation standards of electric carbon steel pipes. Manufacturers should establish a complete quality management system to conduct strict inspection and testing of raw materials, semi-finished products and finished products. In addition, regular quality reviews and product sampling inspections are also essential to ensure that every steel pipe shipped meets industry standards. Steel pipes must be accompanied by quality certification documents such as factory certificates, material lists and test reports (including water pressure tests, ultrasonic and X-ray tests) when leaving the factory.

3. Application requirements
In the power industry, carbon steel pipes are mainly used to transport high-temperature and high-pressure media such as steam and hot water. Therefore, during the application process, it must be ensured that the steel pipe can withstand the corresponding pressure and temperature. At the same time, according to different use environments and medium characteristics, it is also crucial to select appropriate steel pipe specifications and materials.

The implementation standards of electric carbon steel pipes are an important guarantee to ensure the safety and reliability of pipeline systems. From manufacturing, quality control to application requirements, every link needs to strictly comply with relevant standards. Only in this way can we ensure the stable operation of the power industry and provide strong support for the economic development of society.

Read more: Schedule 80 Carbon Steel Pipe or Seamless vs Welded pipe