On the evening of the 14th, the Hubei Provincial People's Government Information Office held a press conference to inform the progress of the rescue and disposal of the gas explosion accident in Zhangwan District, Shiyan City. Up to now, this accident has caused 25 deaths. At present the scene search and rescue is still continuing.

gas explosion

first of all, we first figure out the cause of the gas explosion, natural gas from the leakage, to gather to reach the limit of the explosion, and then to the point of detonation of the three steps are indispensable.

1, the household's natural gas equipment in the pipeline jacks, stoves, plastic hoses in these three areas are very likely to leak

Pipeline socket leakage is mainly due to the quality of the construction and unauthorized removal of the user caused by the stove leakage is mainly due to the quality of the product stoves, plastic hoses leakage is due to the long term not to remove and replace or the plastic hose quality is very poor, resulting in a gas explosion. Plastic hose quality is very poor, resulting in cracking, and most people always think that usually did not move it, a few years past the appearance of no problem. This is a safety hazard.

2, the explosion limit category, said the natural gas leakage is not horrible, the horror is the leakage of the site of poor natural ventilation, resulting in confined space. This time has long been very dangerous, so once encountered with fire, spark discharge are will be an instant explosion.

So if you smell the odor of natural gas leaks, the first thing you don't do is hit the lights! Secondly, do not pull out the phone in the room, exit to a wide place to look for help. The only very simple way to prevent a gas explosion is to open a window in the dining room kitchen at all times! Ultimately, the density of natural gas is lighter than gas, only natural ventilation is excellent, even if a leak, will float out, not easy to explode.

Long-distance pipeline overpressure explosion is rare, generally as long as the explosion that is a leak.

The cause of leakage is mainly due to erosion and physical damage, chemical waste discharge, and the soil layer to produce a primary cell reaction is the key way of erosion, the most deficient position is the weld, and the weld leakage is usually insufficient pressure resistance and is the result of the cumulative effect of the erosion of the two-way effect: the welding is not very good, the point of the pressure resistance to self-care ability is poor, coupled with the erosion, the high pressure of the gas immediately break the point of the least, causing leakage. This will cause leakage. There are also physical damages, which are divided into two types: natural disasters and man-made damages. Geological formations, landslides, foundation settlement, and partial collapses have a high possibility of crushing or destroying the pipelines. Human damage is also divided into two kinds, one is direct damage, one is indirect damage.

Direct damage is some industrial equipment, such as excavators, drilling equipment immediately dry to the pipeline, resulting in damage to the pipeline leakage, or part of the pressure-resistant working ability to weaken, and then leakage. Pipeline foundation depth requirement is a minimum foundation depth of 1.5m at the top of the pipe, so engineering construction damage to the pipeline is very easy to produce. Indirect damage is such as engineering blasting or engineering construction caused by strong vibration, change the pipeline on the ground stress all over, is also very likely to lead to part of the destruction or pressure-resistant working ability to become weaker, and finally cause leakage.

This thing from the scene of the explosion of the scale of operation seems to be, there must be a lot of gas deposits, as people water Xu Xin city streets, if it is the pavement deposits, perhaps already choked the tenants can not stand. I distinguish, may be underground gas pipeline leakage, and underground must also have sufficient indoor space to collect gas.

Because of the historical legacy of time, there are some big cities, the gas pipeline is changed back from the previous liquefied petroleum gas pipeline, the body of the wet gas into dry gas, there are certain safety hazards. In addition, due to the pipeline's material problems, the last century paved pig iron pipeline buried in the ground, how much time will produce leaching, is also a difficult point.

But the gas company will have a technical professional safety inspection line staff, Shiyan will produce that kind of safety accidents, and the local gas company safety inspection line staff dereliction of duty is inseparable. At the same time, the gas company's scale of operation is mixed, and some small gas companies have limited capacity and insufficient staffing, resulting in negligence for some reason (it is uncertain at this stage which gas company is involved). Small gas companies because of the overall strength, lack of funds, some significantly brittle, urgent solution to the problem of procrastination, all over the country, there are such conditions, but also left the ups and downs of the safety hazards.

First of all, the explosive limit of gas in the category of 5% ~ 15%, the concentration of natural gas in the air in this category, when the fire will immediately explode, beyond this category always produce ignition. Therefore, it seems from the scene should be underground gas pipeline leakage and build up to the underground confined space, and then meet with the fire caused by the explosion. I think it may be natural gas pipe leakage, due to some reasons (the construction of the project did not maintain a good safety interval, not in accordance with the map of the project construction, etc.), flowing to the water fall pipe sewage pipe (the two kinds of pipe there is a lot of confined space, in line with the standards of the explosion) rushed into the streets of the community, and some people threw a cigarette butt to the wells immediately resulting in an explosion.

The accident I analyze the repair team may be the trouble:

From the current stage of the case published on the Internet leads to see, the explosion is likely to repair the whole process of many not according to the standards of the actual operation of the opening of the unfortunate.

1, producing an explosion is a farmers' market, rather than a residential neighborhood.

2, the explosion before the gas company and firefighters have long been on the scene, the explosion produced in the processing.

3, 5:00 in the morning on some people alarm that natural gas leaks, but the gas company maintenance team in several areas to come is not clear, it is likely to come late.

4, there is understanding of the gas company's maintenance of the netizen posting guess maintenance staff is likely to have made a mistake. For example, they did not turn off the gate valve and set the warning as required by the standard.

5, firefighters are also likely to have made incorrect, for example, they did not immediately fire evacuate people.

6There should have been someone from the gas company or a firefighter involved in the death or injury.

Property management also has certain obligations, older housing property management fees are much smaller than new housing, itself is full of loopholes. Like the safety accident site such as the old neighborhood, I am afraid that the property management services and services have long been gone.

And even if the domestic property companies and owners' committees are in charge, their powers are far less than those of the HOA. There are far too many cases of indiscriminate gas hookups.

This safety incident in this kind of pure store explosion is really good, just a unique scenario of high traffic, if the bottom of the old residential neighborhood housing to commercial, the explosion will lead to higher damage.

But this is also difficult to understand, as I began to say. China has long produced this type of solid logical thinking. You can't buy an old, highly-aged school district and charge you 5 dollars for property management while charging 2 dollars for a new residential neighborhood that doesn't accommodate anyone.

And then there is, second and third tier cities and some of their older planning areas, pipeline network renewal and renovation refurbishment costs are too high to press the ability to work to move. And many of the planning area is full of after the change of gas, and not like the new area a variety of pipeline network overall planning effectively. Many of the regional gas pipeline network storage are in the decade above, really can be maintained to foolproof, in the final analysis is unlikely.