As an important basic raw material of modern industry, gas products are widely used in metallurgy, steel, petroleum, chemical industry, machinery, electronics, glass, ceramics, building materials, construction, food processing, medicine and other sectors, using a large number of common gases or special gases. The key technology of whether the high purity gas that meets the requirements can be sent to the gas point and still maintain the quality of qualified; High purity gas piping technology is an important part of high purity gas supply system, including the correct design of the system, the selection of pipe fittings and accessories, construction, installation and test. The application of gas, especially for the high-tech in these fields has an important impact, is its indispensable raw material gas or process gas. Only with the needs and promotion of various emerging industrial sectors and modern science and technology, gas industrial products can be developed by leaps and bounds in terms of variety, quality and quantity.

The use of gas has always played an important role in the semiconductor process, especially the semiconductor process has been widely used in various industries, such as the traditional ULSI, TFT-LCD to the current micro-electro-mechanical (MEMS) industry, are based on the so-called semiconductor process as a product manufacturing process. Processes such as dry etching, oxidation, ion planting, film deposition, etc., all use a considerable amount of gas, and the purity of the gas has a decisive impact on component performance, product yield, and the safety of the gas supply is related to the health of personnel and the safety of plant operations.

The significance of high purity pipeline in high purity gas transportation

In the process of stainless steel smelting, about 200g of gas can be absorbed per ton. After stainless steel is processed, not only its surface is stuck with various pollutants, but also a certain amount of gas is retained in its metal lattice. When there is gas flow in the pipeline, this part of the gas absorbed by the metal will re-enter the air stream and pollute the pure gas. When the air flow in the pipe is discontinuous flow, the pipe absorbs the gas through the pressure, and when the air flow stops passing, the gas adsorbed by the pipe forms a decompression analysis, and the resolved gas also enters the pure gas in the pipe as impurities. At the same time, the adsorption and analysis cycle is repeated, so that the metal on the inner surface of the pipe will also produce a certain powder, and this metal dust particles will also pollute the pure gas in the pipe. This characteristic of the pipe is crucial, in order to ensure the purity of the transported gas, not only requires the inner surface of the pipe to have a very high smoothness, but also should have a high wear resistance.

When the gas with strong corrosion performance is used, the corrosion-resistant stainless steel pipe must be selected for piping, otherwise, the pipe will have corrosion spots on the inner surface due to corrosion, and a large piece of metal will be peeled or even perforated in serious cases, thereby polluting the pure gas transmitted and distributed.

The connection of high-purity and high-cleanliness gas transmission and distribution pipelines with large flow rates is all welded in principle, and the pipes required to be used do not change in the organization of welding. When the material containing too much carbon is welded, the air permeability of the welding part makes the gas inside and outside the pipe penetrate each other, destroying the purity, dryness and cleanliness of the conveyed gas, resulting in all our efforts to lose meaning.

In summary, for high-purity gas and special gas transmission pipelines, it is necessary to use a high-purity stainless steel pipe with special treatment, so that the high-purity pipeline system (including pipelines, pipe fittings, valves, VMB, VMP) plays a crucial role in the high-purity gas distribution.

Clean technology of distribution pipeline

High purity and clean gas transmission pipelines refer to certain requirements or controls on the "gas purity, dryness, cleanliness" of the transported gas.

Gas purity: The content of the impurity atmosphere in the gas, usually expressed as a percentage of the purity of the gas, such as 99.9999%, and also expressed as the volume ratio of the impurity atmosphere content ppm, ppb, and ppt.

Dryness: The amount of trace moisture in the gas, or humidity, usually expressed as the dew point, such as the atmospheric dew point of -70. C.

Cleanliness: The number of pollutant particles contained in the gas, particles with a particle size of µm, how many particles /M3 are expressed, and for compressed air, how many mg/m3 of the inevitable solid residue is also expressed, which covers the oil content.

Pollutant size classification: Pollutant particles, mainly refers to the pipeline erosion, wear, corrosion of metal particles, atmospheric dust particles, as well as microorganisms, bacteriophages and wet gas condensation droplets, etc., according to the size of their particle size is divided into:

1. Large particles - the particle size is above 5μm

2. Particle - material diameter between 0.1μm-5μm

3. Ultrafine particles - particle size less than 0.1μm.

Control standard for cleanliness of high purity gases in industrial production