1、 Gas cylinder definition

The Regulations on Safety Supervision of Special Equipment includes cylinders into special equipment for national safety supervision and management. A gas cylinder is defined as a mobile pressure volume containing gas, liquefied gas and liquid with a standard boiling point equal to or lower than 60 ℃ whose nominal working pressure is greater than or equal to 0.2MPa (gauge pressure) and the product of pressure and volume is greater than or equal to 1.0MPa · L.

In today's society, no matter in the production field or in the life field, gas cylinders are indispensable. Gas cylinders are incomparable to other equipment and containers in terms of their wide range of use, large number, variety and large mobility.

Most of the media filled in the gas cylinder are flammable, explosive, toxic, and even highly toxic and corrosive. A little negligence will lead to leakage or explosion, fire and poisoning, which will lead to catastrophic accidents. It has caused heavy losses to the national economic development and people's lives and property.

2、 Classification of gas cylinders

I. Classification by filling medium

⑴ Permanent gas cylinders, such as oxygen cylinders, hydrogen cylinders, carbon monoxide cylinders, etc;

⑵ High pressure liquefied gas cylinders, such as carbon dioxide gas cylinders, ethane gas cylinders, ethylene gas cylinders, etc;

(3) Low pressure liquefied gas cylinders, such as ammonia cylinders, chlorine cylinders, liquefied petroleum cylinders, etc;

(4) Dissolved gas cylinders, such as dissolved acetylene cylinders.

 II. Classification by structure

⑴ Seamless gas cylinders are made of steel ingots or seamless steel tubes by heating, stretching and necking, and the cylinder body has no seams;

(2) The welded cylinder body is made by welding, which can be divided into two assemblies (upper and lower cup heads are assembled by one circumferential welding) or three assemblies (upper and lower heads and cylinder body are assembled by one longitudinal weld and two circumferential welds).

III. Classification by material

⑴ Steel gas cylinder

Carbon steel gas cylinder, seamless gas cylinder, C ≤ 0.40%, welded gas cylinder, C ≤ 0.22%;

Manganese steel gas cylinder Seamless gas cylinder material contains Mu 1.40%~1.75%, welded gas cylinder material contains Mu ≤ 1.60%;

Chromium molybdenum steel cylinder material contains Cr 0.80%~1.10%, Mo 0.15%~0.25%;

Stainless steel gas cylinders are made of 8% Ni and 18% Cr. They are used for high purity gas cylinders and highly corrosive gas cylinders.

⑵ The aluminum alloy cylinder is made of aluminum as the main alloy material, which has the advantages of excellent low-temperature impact performance, light weight, corrosion resistance, etc.

(3) Composite gas cylinders are made of two or more materials.

The glass fiber reinforced plastic cylinder is a composite cylinder with metal as the inner cylinder (liner), high-strength fiber wrapped on the outer side and plastic curing as the reinforcing layer;

Wire wound gas cylinder A composite gas cylinder in which one or more layers of high-strength steel wires are wound outside the cylinder body as reinforcing layers to improve the cylinder strength.