What caused this oxygen tank to explode?
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September 9th, around 4 p.m. While carrying out oxygen-acetylene cutting operations at a certain workstation of a company’s subsidiary, the worker attempted to close the valve on the oxygen cylinder after completing the task; the oxygen cylinder exploded, resulting in 1 death. What causes this? Let me clarify first: it is an indoor task, so there is no risk of oxygen cylinders exploding. Is it a defect in the oxygen cylinder itself, an issue with the filling, or improper operation by the personnel?
Sharing an incident of an oxygen cylinder explosion. At 17:40 on May 5, 2011, after completing the task of cutting steel plates, Lu X, an oxy-welder from the water and electricity maintenance team at the Tarim Oil Field property service center, experienced an explosion of the oxygen tank while cleaning up the work site and turning off the pressure regulator of the oxygen tank. Cause analysis: That afternoon, an incident investigation team was established at the mining site. The following issues were found on site: 1. There was oily substance at the bottom of the oxygen cylinder. When oily substances come into contact with high-purity oxygen, a chemical reaction occurs that releases heat, directly causing an explosion. 2. This oxygen cylinder was originally labeled as a nitrogen cylinder upon leaving the factory; however, the oxygen production facility violated the provisions set out in the **Quality Supervision Bureau’s Document No. [2000]250, ‘Regulations on the Safety Inspection of Gas Cylinders’, which prohibit the mixed use of different types of gas cylinders. They filled it with oxygen without authorization and painted it sky blue. 3. The oxygen cylinder shows that its last inspection date was in November 2001. In accordance with the \"Regulations on the Safety Supervision of Gas Cylinders\" issued by the Quality and Technical Supervision Bureau under document No. 【2000】250, inspections are required every 3 years; thus, this cylinder has missed 3 inspections in total, resulting in 10 years without any inspection. Moreover, the manufacturer is unable to provide the cylinder’s historical inspection reports. 4. This oxygen production facility is operating beyond the scope permitted by its license; its license for handling hazardous chemicals allows for the production and sale of nitrogen, carbon dioxide, argon, and acetylene only, and it does not have the authority to produce or sell oxygen. 5. In terms of management, there are still issues with the inspection of gas cylinders upon entry into storage. First, the warehousing acceptance system is imperfect, with a lack of institutional requirements for reviewing the inspection certificates of oxygen cylinders. Second, the implementation of existing regulations is merely a formality; only the quantity, appearance, pressure, and oxygen certification are checked, while there is no strict inspection of the cylinder’s steel stamp markings, inspection date, or cylinder color. No violation was found regarding the oxygen cylinder being modified from a nitrogen cylinder. Third, contractors supply beyond their scope, and qualification checks are not strict enough.
The causes of the explosion can be various, and it will only be possible to determine them after an on-site investigation; what is discussed here is merely a list of possible causes...
Logically, as pressure is applied to the gas, its pressure should decrease; it will explode sooner or later – it’s likely due to tempering.
There is a possibility of tempering, whether the oxygen cylinder is statically grounded, and whether it has been inspected before being filled
The gas cylinder itself, the operation process, the operating environment, and so on can all cause problems with the gas cylinder. The specific details should be determined based on on-site investigation.
Worker gloves with oil stains + cylinder defects = explosion? ? ?
It can’t be tempered. It is understood that operations have been stopped for quite some time now