Now household life often use the liquid gas, commonly known as the gas cylinder is a vessel carrying liquid gas. "Gas" is the transportable pressure vessel steel, with explosion danger and its wall thickness is only 2.5 mm wall thickness (new cylinder factory calibration), very thin, it is always under pressure from internal medium produces, normal when using internal pressure (pressure) 0.5 ~ 1.2 million PASCAL (5 ~ 12 kg/cm2), the tensile strength of the cross section to withstand 1000 kilograms. "Gas" in the process of long-term filling, transportation, use collision, insolate, medium corrosion damage, will produce fatigue crack corrosion, pits, variant, defects such as thinning, these shortcomings is the direct cause of the explosion.
"Gas", the instantaneous produces twice, starting with tanks burst physical explosion, 250 ~ 300 times liquid petroleum gas instantaneous expansion into gas, produce shock waves, like mine explosion. Into gaseous LPG mixed with air quickly, when in the air concentration, down to 3 ~ 11% in case of fire, will produce chemical explosion, the whole gas explosion combustion space, produce enormous shock waves, harm life, burning property, damage to buildings, with a secondary disaster, if a man in this kind of explosive gas, will make the respiratory tract and lung tissue damage, dreadful.
From to ensure the safety of people's life, the "special equipment safety supervision regulations" promulgated by the state council will be liquefied petroleum gas cylinder as legal supervisory equipment. "Gas" is not a permanent durable goods, through a large number of professional and technical personnel accident case analysis and scientific experiments, measured "gas" safe use period of 15 years, during which a regular inspection, every four years in order to find out defects.