The laboratory gas supply system acts as the lifeline of scientific research experiments, which directly affects the accuracy of experimental data and personal safety of staff. Nevertheless, improper system design in many laboratories easily leads to gas leakage, unstable pressure and even serious safety accidents. This article systematically introduces the key design points of laboratory gas supply systems, helping you build a safe and efficient laboratory working environment.
Part 1 Understanding Laboratory Gases
1.Inert gases such as nitrogen and argon: These gases are non-flammable, yet high concentrations may cause suffocation risks.
2.Flammable and explosive gases such as hydrogen and methane: Strict anti-leakage measures and static electricity protection shall be implemented for these gases.
3.Toxic gases such as chlorine and hydrogen sulfide: Gas leakage alarm devices and emergency response facilities must be fully equipped.
4.Corrosive gases such as hydrogen chloride and ammonia: All connecting pipelines shall be made of corrosion-resistant materials.
Note: All gas cylinders shall be stored in classified areas independently. Flammable gases including hydrogen need to be placed in separate storage spaces.
Part 2 Core Design Principles of Laboratory Gas Supply Systems
1.Safety priority: Implement full-range protection against gas leakage, flashback and static electricity hazards.
2.Stable gas supply guarantee: Keep the pressure fluctuation range within ±10% to ensure steady gas delivery.
3.Modular layout design: Reserve extended connecting interfaces to meet the demand of adding new gas types in future use.
4.Cost control optimization: Reasonably control the procurement cost of raw materials and supporting equipment on the premise of meeting all safety operation standards.
Part 3 Key Design Points of Laboratory Gas Supply Systems
1. Selection of Pipeline Materials
- Copper pipes: Suitable for most inert gases and partial corrosive gases including oxygen and nitrogen, featuring high pressure resistance and easy processing performance.
- 316L stainless steel pipes: Ideal for high-purity gases such as electronic grade special gases with outstanding anti-corrosion performance.
- PTFE lined pipes: Specially applied for highly corrosive gases like hydrogen fluoride and chlorine.
Prohibition rule: Copper pipes are strictly forbidden for acetylene gas delivery, as chemical reaction will generate explosive copper acetylide.
2. Pressure Reduction System Design
- Primary pressure reducing valve: Installed at the outlet of gas cylinders, which lowers the original high pressure of 15MPa down to 1MPa to 1.5MPa.
- Secondary pressure reducing valve: Mounted in front of terminal experimental equipment, used to stabilize the final output pressure between 0.2MPa and 0.5MPa.
Core reminder: Two-stage pressure reduction structure must be adopted for flammable gases such as hydrogen to avoid safety hazards caused by sudden pressure changes.
3. Semi-automatic Manifold Assembly
Function feature: Two groups of gas cylinders are connected in parallel. When the main cylinder runs out of gas, the system can switch to standby cylinders automatically to realize uninterrupted continuous gas supply.
Selection suggestion: It is recommended to select products equipped with real-time pressure display and abnormal pressure alarm functions.
4. Flow Meter Configuration
- Mass flow meter: Featured with high measurement accuracy, perfectly matching experimental scenarios requiring precise flow control such as gas chromatography experiments.
- Float flow meter: Cost-effective and practical, widely applicable for conventional daily laboratory experiments.
Installation suggestion: Install an independent flow meter at the air inlet of each experimental device for separate flow adjustment and control.
Part 4 Standard Maintenance and Management Regulations
1. Routine Daily Inspection
- Conduct air tightness inspection on all pipeline joints every week by using soapy water detection method to check potential gas leakage.
- Calibrate the actual output pressure of pressure reducing valves every month to confirm all parameters conform to operating requirements.
2. Emergency Handling Measures for Gas Leakage
- Cut off the gas source immediately and turn on the whole-site ventilation system rapidly once leakage occurs.
- Avoid switching any electrical equipment when flammable gas leaks, so as to prevent open sparks from triggering combustion and explosion risks.
3. Standard Management of Gas Cylinders
- Store empty cylinders and fully filled cylinders in separate zones with obvious classification signs posted clearly.
- Fix hydrogen cylinders with anti-toppling chains to prevent accidental dumping and collision.
4. Daily Maintenance of Pressure Reducing Valves
- Disassemble, clean internal components and replace aging sealing rings for all valves on an annual basis.
- Keep oxygen pressure reducing valves away from all grease and oily substances, which may easily cause combustion and explosion accidents.
