Schedule of gas cylinder inspection

As a container for storing and transporting various gases, gas cylinders are widely used in industry, medical treatment, aviation, diving and other fields. Since gas cylinders are subjected to high pressure, high temperature, low temperature, impact and other external forces during use, they are prone to problems such as overuse, internal defects and corrosion, so they need regular inspection and testing. This article will introduce the inspection cycle and relevant regulations of gas cylinders in detail.

Inspection cycle of liquefied gas cylinders

Liquefied gas cylinders mainly include liquefied petroleum gas cylinders, liquefied natural gas cylinders, liquefied oxygen cylinders, liquefied nitrogen cylinders, liquefied argon cylinders, liquefied helium cylinders, liquefied carbon dioxide cylinders, etc. According to GB/T9251-2011 standard, the inspection cycle of liquefied gas cylinders is as follows:

- First inspection: Within 6 years of service, new purchases and re-openings meet the specified conditions, no inspection is required.
- Secondary inspection: For those who have been in service for more than 6 years or have been inspected once; it is conducted every 3 years.
- Third-level inspection: After the secondary inspection, it continues to be in service; it is conducted every 2 years.
- Level 4 inspection: if the cylinder continues to be in service after the level 3 inspection, it shall be conducted once a year.

Inspection cycle of compressed gas cylinders

Compressed gas cylinders mainly include oxygen cylinders, nitrogen cylinders, argon cylinders, carbon dioxide cylinders, etc. According to GB/T5099 standard, the inspection cycle of compressed gas cylinders is as follows:

- First inspection: if the cylinder is newly purchased, refilled or returned to service after repair, an acceptance inspection shall be conducted.
- Level 2 inspection: the remaining pressure vessels shall be inspected once every 6 years.
- Level 3 inspection: before the second and subsequent tests, an intermediate inspection shall be conducted.

Inspection cycle of gas mixture cylinders

Gas mixture cylinders mainly refer to cylinders made of three gases, namely carbon dioxide, nitrogen and oxygen, which are mainly used in beverages, electronics, aviation and other fields. According to GB/T18205 standard, the inspection cycle of gas mixture cylinders is as follows:

- First inspection: if the cylinder is newly purchased or refilled and meets the specified conditions within 6 years of service, no inspection is required.
- Level 2 inspection: if the cylinder has been in service for more than 6 years or has been inspected once, it shall be conducted once every 5 years.
- Level 3 inspection: if the cylinder continues to be in service after the level 2 inspection, it shall be inspected every 3 years.

Inspection cycle of oxygen cylinders

Oxygen cylinders refer to cylinders used to store medical oxygen, which are commonly used in hospitals, ambulances and other places. According to the YY0640-2008 standard, the inspection cycle of oxygen cylinders is as follows:

- First inspection: if the cylinders are newly purchased or remanufactured and meet the specified conditions within 6 years of service, no inspection is required.
- Level 2 inspection: if the cylinders have been in service for more than 6 years or have been inspected once, it shall be inspected every 3 years.
- Level 3 inspection: if the cylinders continue to be in service after the level 2 inspection, it shall be inspected every 2 years.
- Level 4 inspection: if the cylinders continue to be in service after the level 3 inspection, it shall be inspected every year.

Inspection cycle of special gas cylinders

- Cylinders containing corrosive gases: inspected every 2 years.
- Cylinders containing general gases: inspected every 3 years.
- Liquefied petroleum gas cylinders: if the cylinders have been in use for less than 20 years, they shall be inspected every 5 years; if the cylinders have been in use for more than 20 years, they shall be inspected in the second year.
- Gas cylinders containing inert gas: check once every 5 years.
- Dissolved acetylene gas cylinders: check once every 3 years.

Inspection standards

Regular inspection of gas cylinders needs to be carried out in accordance with relevant national standards, generally including the following aspects:

- Appearance inspection of gas cylinders: check the appearance of gas cylinders to see if there are pits, dents, corrosion, leakage, etc.
- Internal inspection: check whether there are cracks, rust or corrosion inside the gas cylinder by dumping, inverting, water pressure test, ultrasonic testing, etc.
- Service life assessment: evaluate the maximum service life of the gas cylinder by checking the service life of the gas cylinder, whether it is used frequently, etc.
- Inspection records: record the inspection process in detail, including inspection time, inspection items, results and other information, for reference during the next inspection.

Inspection agency

Regular inspection of gas cylinders needs to be carried out by an inspection agency that meets relevant national requirements. Generally, only nationally certified inspection agencies are authorized to conduct regular inspections of gas cylinders.

Conclusion

Gas cylinders are commonly used containers for storing compressed gas. To ensure the safe use of gas cylinders, users should conduct regular inspections in accordance with regulations. Before using gas cylinders, they must be inspected to ensure that they are intact. Through regular inspections, potential problems can be discovered and resolved in a timely manner, accidents caused by gas cylinder failures can be prevented, and the safety of users' lives and property can be protected.