How to Specify the Medium in the Process Parameters of a Pressure Vessel?
The term "medium" in the context refers to the substance contained in the pressure vessel, existing in a liquid, gaseous, or gas-liquid mixed state. The safety of pressure vessels is intricately linked to the nature of the contained media. Different characteristics of the media necessitate varied requirements for the material, manufacturing, and utilization of the container. Pressure vessels may contain flammable, explosive, corrosive, or toxic substances, requiring careful attention during both usage and maintenance.
(1) Toxic Media:
According to GBZ230's "Classification of Hazard Degree of Occupational Exposure to Toxic Substances," toxic media are categorized into four levels:
Level I: Extremely hazardous, Allowable concentration <0.1mg/m3
Level II: Highly hazardous, Allowable concentration 0.1~<1.0mg/m3
Level III: Moderate hazardous, Allowable concentration 1.0~<10mg/m3
Level IV: Mild Hazardous, Allowable concentration ≥10mg/m3
(2) Flammable Media:
Refers to a gas-air mixture with a lower explosion limit of less than 10% or a difference between the upper and lower explosion limits of more than 20%.
(3) Mixed Media:
In cases where the medium in the pressure vessel is a mixed substance, the determination of toxicity and flammability should be based on the composition of the medium and the principles outlined in the process design by the design unit or the production technology department of the user unit.
(4) Corrosive Media:
Highly corrosive substances, such as nitric acid, sulfuric acid, hydrochloric acid, naphthenic acid, strong alkali, exhibit strong corrosiveness. Due to variations in media types, properties, and process conditions, the corrosive nature of the media can differ significantly.
(1) Toxic Media:
According to GBZ230's "Classification of Hazard Degree of Occupational Exposure to Toxic Substances," toxic media are categorized into four levels:
Level I: Extremely hazardous, Allowable concentration <0.1mg/m3
Level II: Highly hazardous, Allowable concentration 0.1~<1.0mg/m3
Level III: Moderate hazardous, Allowable concentration 1.0~<10mg/m3
Level IV: Mild Hazardous, Allowable concentration ≥10mg/m3
(2) Flammable Media:
Refers to a gas-air mixture with a lower explosion limit of less than 10% or a difference between the upper and lower explosion limits of more than 20%.
(3) Mixed Media:
In cases where the medium in the pressure vessel is a mixed substance, the determination of toxicity and flammability should be based on the composition of the medium and the principles outlined in the process design by the design unit or the production technology department of the user unit.
(4) Corrosive Media:
Highly corrosive substances, such as nitric acid, sulfuric acid, hydrochloric acid, naphthenic acid, strong alkali, exhibit strong corrosiveness. Due to variations in media types, properties, and process conditions, the corrosive nature of the media can differ significantly.
