Installation requirements for laboratory gas supply system pipelines

Installation requirements for laboratory gas supply system pipelines　

Meet the requirements and safety of different experiments. The double bottle adopts a busbar gas supply equipment, which has manual, semi-automatic and fully automatic switching functions, and is equipped with a low-pressure alarm device to monitor the pressure, concentration detection alarm and exhaust in real time, ensuring the normal use of gas and the safety of life and property of customers.

Common equipment for pneumatic systems

Steel cylinder (gas compressor), steel cylinder fixing bracket, steel cylinder cabinet, steel cylinder joint, metal hose, semi-automatic switch device, primary pressure reducer, secondary pressure reducer, welded tee, welded large and small head, clamping sleeve valve, stainless steel pipe (BA), pressure gauge, combustible and toxic gas monitoring and alarm device, etc.

Technical requirements for centralized gas supply system in laboratory

Gas cylinder storage room

Solid walls with a thickness of 300mm should be used between gas cylinders, and explosion-proof doors and windows should be installed

Indoor electrical equipment should have explosion-proof function

Exhaust fans should be installed to maintain good ventilation at all times

The gas supply system requires two-stage depressurization gas supply. Reduce the pressure of the gas supply manifold. The gas is depressurized from 15MPa to less than 1.5MPa and then transported to each gas usage laboratory. The secondary pressure reducer is installed in each gas laboratory or gas point to facilitate unified control of the gas delivery pressure of the fume hood or instrument. The gas terminal is equipped with a medium pressure ball valve and a pressure indicator. The secondary pressure regulator precisely adjusts the pressure (0.01 megapascals) to obtain stable pressure, which can meet the requirements of the instrument for different operating pressures. Both the primary and secondary pressure reducers are equipped with pressure gauges that can display the current pressure in real time.

Adopting a semi-automatic dual busbar system for continuous gas supply, laboratory usage requirements. When replacing the gas cylinder, the clamping sleeve installed under the high-pressure hose can be used to replace the gas cylinder

Hydrogen and acetylene are. Gas leakage detection and alarm devices should be designed, and flame arresters should be installed to prevent the backflow of open flames. Adequate safety distance should be ensured for placing flammable and combustible gases.

Laboratory high-purity gas path layout

The layout of high-purity gas pipeline systems is different from that of ordinary gas pipelines. Generally speaking, it is required that the pipeline should not be too long and there should be no dead corners, such as "blind pipes" that are difficult to blow clean. Necessary discharge and sampling ports should be provided at the end of the main or branch pipe. In some non continuous users, allow a small amount of gas to be continuously discharged at the end of the pipeline, so that the gas in the pipeline will flow normally and avoid "dead zones". According to the quality requirements of the process gas, terminal purification devices should be installed if necessary. 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.

High purity gas pipeline and pipeline 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 needs to reach 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 material characteristics of the pipeline for transportation 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.

Installation requirements for gas supply system pipelines

The pipeline laying should meet the design requirements. If there are no requirements in the design, the dry gas pipeline should be installed horizontally; The pipeline for transporting moisture should be installed with a slope of not less than 0.003, and the slope should face the condensate collector.

The pipeline is connected by welding, with tungsten inert gas arc welding as the base and manual arc welding as the cover. Stainless steel pipe welding or spot welding should be protected by argon filling

Gas pipelines and equipment, valves, and other accessories should be connected by flanges or threads. The filling material for threaded joints must be polytetrafluoroethylene film

When gas pipelines pass through clean rooms, the exposed parts of flange gaskets or threaded packing must be cleaned thoroughly

When using sandblasting rust removal or acid pickling passivation seamless steel pipes for gas pipelines, a centralized installation method must be adopted. The installation should be combined in sections within 48 hours, protected by nitrogen gas, and the filling pressure should not be less than 0.2 megapascals

　Installation requirements for laboratory gas supply system pipelines