Equipment accident

Pressure vessel

The size of equipment accident rate has many influencing factors and is very complicated. It is not only related to the various technical levels of the entire industrial field, but also related to social culture and human quality.

Under the same conditions, the accident rate of pressure vessels is much higher than that of other mechanical equipment. Originally, most pressure vessels bear static and relatively stable loads. They are not prone to failure due to excessive wear like general rotating machinery, nor are they prone to fatigue failure due to high-cycle repeated loads like high-speed engines. The reasons are mainly as follows.

Technical conditions

1) The use conditions are relatively harsh. Pressure vessels are not only subjected to pressure loads of different sizes (in general, pulsating loads) and other loads, but some are still operating under high temperature or deep cold conditions. The working medium is often corrosive and the working environment is relatively harsh. .

2) Easy to overload. The pressure in the container often rises rapidly due to operational errors or abnormal reactions, and often the container has ruptured before it is discovered.

3) The local stress is more complicated. For example, around the opening of the container and other structural discontinuities, fatigue and rupture are often caused by excessive local stress and repeated loading and unloading.

4) Serious defects are often hidden. Welded or forged containers often leave serious defects such as micro cracks during manufacture. These defects will suddenly rupture if they continue to expand during operation or under appropriate conditions (such as use temperature, nature of working medium, etc.).

Use management

1) The use is illegal. Purchase equipment produced by factories without pressure vessel manufacturing qualifications as pressure-bearing equipment, and illegally use them as pressure vessels to avoid safety supervision and management such as application for installation, use registration, and inspection, leaving endless troubles.

2) Although the container is legal, the management operation does not meet the requirements. The enterprise does not have or lacks technical management personnel who understand the professional knowledge of pressure vessels and understand the relevant national regulations and standards for pressure vessels. Pressure vessel operators without the necessary professional training and assessment, and work without a certificate, can easily cause operation accidents.

3) Pressure vessel management is in a “four no” state. That is, one has no safety operating procedures, two has no pressure vessel technical files, three has no pressure vessel certificated personnel and related management personnel, and four has no regular inspection management. Make pressure vessels and safety accessories in an out of control state of blind use and blind management.

4) Unauthorized change of use conditions, unauthorized repair and transformation. Operators ignore the safety of pressure vessels, and in order to adapt to the needs of a certain process, they arbitrarily change the purpose and conditions of use of pressure vessels, and even carry out “sick” operations, and cause serious consequences such as illegal overload and overpressure production.

5) The safety supervision and management departments of local governments and relevant administrative law enforcement departments are not in place. The work of safety supervision and management departments and relevant administrative law enforcement departments failed to use the development of the socialist market economy, especially the proliferation of small and widely distributed private and private enterprises, which caused blind spots and inadequate management of pressure vessel safety supervision and management. This phenomenon has contributed to the illegal use and management of pressure vessels.