What are the requirements for laboratory gas circuits?

The laboratory gas pipeline refers to the pipeline engineering that connects the gas cylinder to the instrument terminal in the laboratory. The installation of laboratory gas pipelines is a systematic process from the main valve of the gas source cylinder station (cylinder room) to various gas valves on the workbenches of related instrument rooms. The gas path system is mainly used as a control equipment for processing high-purity gases, toxic gases, and corrosive gases, and is a truly laboratory specific gas path system.

One overview

Modern large laboratories, factory workshops, and various types of analytical instruments such as chromatography, mass spectrometry, or atomic absorption instruments require continuous use of carrier gases and fuel gases due to gas consumption. Therefore, laboratory management workshops need to consider how to ensure a continuous and stable supply of these gases, which can be achieved through the use of high-pressure gas cylinders, liquid Dewar flasks, or a combination of centralized supply systems. Based on safety and efficiency factors, without considering the economic factors of instruments, centralized gas supply systems have become more common and become a high-purity continuous and reliable supply of natural gas. In some cases, even local fire safety regulations recommend gas cylinders as designated areas, and the main source of a liquid storage Dewar flask is placed outside the work area, and then the gas is transported to the plants and laboratory through a pipeline system, pressure is regulated, and easily installed on the workbench by using two point reducers.

II characteristic

The research on the characteristics of gas supply systems mainly focuses on four development aspects: safety, economy, purity, and work management processes.

Safety: Even if the steel cylinder is still used for gas supply, it is placed in a safe area outside the work area, and users can cut off the gas supply in emergency situations through the equipped remote cut-off system. The reasonable arrangement of steel cylinder storage areas can maintain a safe distance between flammable and combustible containers, eliminate high-pressure equipment attached to the workplace, and avoid potential risks of toxic or flammable gas leaks. The operation of steel cylinders must still be carried out by trained and qualified personnel to reduce the occurrence of major accidents.

Economy: Establishing a centralized gas cylinder allows for storage between limited laboratory spaces without the need to cut off gas cylinders for replacement, saving time and ensuring continuous gas supply. Users only need to manage fewer cylinders and pay less rent for cylinders, as they use the same gas from all points of the same gas source. This mode of supply will ultimately reduce transportation costs, decrease the remaining amount of gas that bottles return to the company, and enable more standardized management of cylinders.

Purity: The panel data of the blowable pressure regulator can reduce the probability of impurities entering the information system by maintaining the specified purity of the gas and reducing the frequency of cylinder replacement.

Workflow: The centralized pipeline gas supply system can place the gas supply port at the point of use, making the workplace design more reasonable; The gas supply process can also be more easily controlled through monitoring and alarm systems In this way, the workflow is significantly optimized.

III Overall requirements

Under the centralized gas supply mode in the laboratory, it is introduced from the laboratory dedicated area through external gas ducts. In addition to directly supplying clean air from the compressed air system, another option is to supply high-pressure gas to the cylinder.

2. Each gas should have a main supply and backup supply bottle, and an automatic mode switching panel data should be installed for system gas supply control to ensure uninterrupted gas supply for the enterprise.

3. Gas is transported through high-quality pipelines, and there must be brackets fixed inside the wall every 1.5 meters. All circuits in the laboratory are installed under the ceiling, and all gas indicating connections are clearly set along the wall. There should be clear signs every 1.5 meters along the gas line indicating the status of the gas.

4. For flammable and combustible gases, it is recommended to use a reduced pressure and install high flame retardant terminals.

5. All pressure reducing valves need to be connected to form an exhaust pipeline that leads to the gas data storage area. Flammable and combustible gas exhaust pipelines cannot be developed and placed together.

6. All designs and constructions must comply with relevant specifications and requirements, such as:

Scientific Architectural Design Laboratory GB50235-1997

Code for Construction and Acceptance of Industrial Metal Pipeline Engineering Projects JGJ91-93

Design Code for Acetylene Station GB50031-91

Design Code for Compressed Air Station GB50029-2003

4 Gas pipeline requirements

1. All of these gases are composed of high-quality copper or stainless steel pipes (BA grade) from the enterprise through the pipeline.

2. Gas pipelines shall not be laid on the same rack as cables and wires.

3. Flammable gases, such as acetylene, are introduced separately from other gases. If the hydrogen pipeline is laid with other parallel pipes, the spacing should not be less than 0.5 meters. Cross laying should be carried out at intervals of no less than 0.25 meters, and the layering should be above hydrogen for pipeline laying.

4. The compressed air has a purification treatment device on the pipeline that filters impurities and moisture. This purification system device needs to be connected in parallel and isolated with a separate valve to facilitate the management and maintenance of the filtering device data.

5. All gas pipelines shall be seamlessly welded and joint fittings shall only be used when connected to valves or regulating valves.

6. Each laboratory must have a separate control valve, pressure gauge, and pressure reducing valve.

7. A separate control valve should be installed on the gas pipeline leading to the workbench, and the control system valves for various gases should be evenly discharged on the workbench

8. Gas pipelines need to be supported every 1.5 meters or so. In addition, according to the bending radius of the gas pipeline, appropriate support positions must be set, and all bends must be supported. All supports in gas pipelines should be galvanized for corrosion prevention.

Five Other requirements

When the opening pipe can be installed on site, after the entire system installation is completed, high-purity nitrogen is used to blow the flow rate to ensure the cleanliness of the entire system.

After the installation of the gas supply system is completed, relevant personnel can conduct strength testing, sealing testing, and stability testing according to the requirements of the enterprise.