Installation and maintenance of laboratory gas pipeline

Installation and maintenance of laboratory gas pipeline　　

The gas path system is mainly used as a control equipment for processing high-purity gases, toxic gases, and corrosive gases. It is a convenient and safe gas path system for laboratory gas supply. Mainly used in high-tech fields such as laboratories, electronic microelectronics, petrochemicals, solar energy, analytical instruments, nuclear power plants, biopharmaceuticals, school research, atomic absorption spectroscopy, waste gas analysis, food packaging, marine industry, medical/industrial laser industry, etc.

1. The pipes, ball valves, clamps, and tees are all made of 316L stainless steel; The pressure reducer is a high-purity gas pressure reducer (stainless steel valve core), and the high-pressure hose (connecting the steel cylinder and busbar) is a stainless steel corrugated pipe. The inlet end of the high-pressure hose is equipped with a one-way valve, which can prevent gas leakage inside the hose during cylinder replacement and prevent external air from entering the gas path.

2. Pipeline system: All gas pipelines are made of bar grade 316L stainless steel pipes, and there are purification devices on the pipes to filter impurities and moisture, so that the gas will not be contaminated by the pipeline system during the circulation process, ensuring the purity of the gas. At the same time, there should be clear signs to indicate the direction of gas flow.

3. Pipeline connection: The busbar and terminal parts are connected through card sleeves, which facilitates the maintenance and management of pressure reducers and valves.

4. Terminal: Each instrument should be equipped with a shut-off valve and a secondary pressure regulator (one for each gas). Globe valves are used to control the opening and closing of each gas path; When the instrument needs adjustment and maintenance, the gas supply to any specific instrument can be stopped. The pressure regulator is used to display and regulate the pressure at the terminal.

1. Stainless steel pipes with clear exterior and clean interior are preferred, followed by copper pipes and plastic pipes. Avoid using plastic pipes for outdoor components.

Indoor components should use stainless steel pipes as much as possible. Polytetrafluoroethylene or polyethylene pipes can be used for special needs.

To eliminate unnecessary hazards and reduce possible leakage points in pipelines, it is recommended to use ultra long stainless steel hoses that are easy to bend and change direction. Sometimes, for the convenience of construction and design, some two-way and three-way joints can be installed in the pipeline.

1. The layout of high-purity gas pipeline systems is different from that of ordinary gas pipelines. Usually, it is required that the pipeline should not be too long and should not have blind spots that are difficult to clean, such as "blind pipes". Necessary discharge and sampling ports should be provided at the end of the main or branch pipe. In some non continuous users, a small amount of gas is continuously discharged at the end of the pipeline, so that the gas in the pipeline will flow normally and there is no "dead zone". According to the quality requirements of the process gas, if necessary, an end purification device needs to be installed. Generally speaking, control valves, filters, pressure reducing devices, pressure gauges, flow meters, online analytical instruments, etc. The high-purity gas pipelines entering the clean room are concentrated in the gas population room for unified management and control.

2. High purity gas pipeline and accessory materials: High purity gas pipeline transportation pipelines should use pipelines of corresponding quality according to different requirements of gas purity, allowable impurity content, particle content, etc. in the process. For example, the semiconductor industry not only requires a clean production environment, but also has specific and strict requirements for various high-purity gases required in the production process due to its complex production process and fine processing. From micrometer technology to sub micrometer and deep sub micrometer (less than 0.35um) technology, the requirements for impurity and moisture content in gases are very strict, and 10-6 (ppm level) cannot meet the requirements. It is necessary to achieve 10-9 (ppb level) or even 10-12 (ppt level), and the dust particle size needs to be controlled within 0.05-0.01 µ m. Therefore, the pipeline material characteristics of the conveying pipeline must meet the requirements of high-purity and ultra high purity gases.

The main characteristics of pipeline materials that affect gas quality for pipelines transporting high-purity gases are breathability, gas release rate, adsorption, surface roughness, wear resistance, and corrosion resistance.

Visual inspection

1. Pipeline wiring should be horizontal, straight, and vertical; The pipe is firmly fixed.

2. There is no obvious damage on the outer surface of the pipeline.

3. Each valve component has no obvious damage. If the pipeline deforms (such as bubbling, twisting, expansion, and other phenomena) after being filled with pressure during the system pressure test, it means that the system cannot operate under this pressure. If the system works under this pressure for a long time, it will burst at the deformed position, causing personal and property damage.

Installation and maintenance of laboratory gas pipeline