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High-Pressure Gas Classification

High-Pressure Gas Classification

Gas is usually classified into three types: compressed gas, liquefied gas, and solution gas. It can also be classified by trait: inflammable gas, oxidizer, and inert gas. It can also be classified by toxicity: toxic and non-toxic.

Classification by state
Classification by state
Type Trait Type
Compressed Gas Resistant to liquefaction when compressed at room temperature since the critical temperature is lower than room temperature. So the compressed gas stays in a gas state. hydrogen, oxygen, nitrogen, methane, etc.
Liquefied Gas Relatively easily liquefied once compressed or cooled since the critical temperature is higher than room temperature. Gas is liquefied in a container. Liquefied ammonia, chlorine, propane, ethylene oxide, etc.
Solution Gas Gaseous reservoir hydrocarbons dissolved in liquid reservoir hydrocarbons because of the prevailing pressures in the reservoir. Also known as dissolved gas. acetylene
Classified by Inflammabilit
Classified by Inflammabilit
Type Trait Type
Inflammable Gas Once fused with oxygen, it creates light and heat. There are 32 types of inflammable gas including hydrogen, methane, ethane, profane, etc. This type of gas burns in the air and has LEL (lower explosive limit) of less than 10%. The difference between LEL and UEL(upper explosive limit) is more than 20%. Methane, ethane, profane, butane, hydrogen, etc.
Inert Gas An inert gas is a gas which does not undergo chemical reactions under a set of given conditions. nitrogen, carbon dioxide, argon, etc.
Oxidizer Gas needed for inflammable gas to burn. Air, oxygen, Chlorine, etc.
Classified by Toxicity
Classified by Toxicity
Type Trait Type
Toxic A gas that can be toxic if there is enough in the air. Permissible concentration lower than 200ppm. Chlorine, ammonia Carbon monoxide, etc.
Non-toxic A gas that is not toxic regardless of the concentration in the air. Oxygen, Hydrogen, etc.

※ Permissible concentration: The maximum concentration of radioactive material in body tissues that is regarded as acceptable and not producing significant deleterious effects on the human organism.

High Pressure According to Gas Safety Management Regulation

High Pressure According to Gas Safety Management Regulation
Category Definition
Compressed Gas Compressed gas that is above 10kg/cm² in common temperature and the actual pressure being more than 10kg/cm². Pressure of 10kg/cm² at 35oc.
Liquefied Gas Liquefied gas that is above 2kg/cm² in common temperature and the actual pressure being more than 2kg/cm². Pressure being 2kg/cm² at 35oc.
Solution Gas Acetylene gas that has a pressure surpassing 0kg/cm² at 15oc.
Special Gas Special gas that has a pressure surpassing 0kg/cm² at 35oc (liquefied hydrocyanic acid, liquefied methyl bromide, liquefied ethylene oxide).