From May 1, 2018, the newly revised national standard “Liquefied Petroleum Gas Bottle Valve” (GB/T 7512-2017) will be formally implemented, which marks the official “posting” of the new national standard after the 2006 version, the national standard The revision was formally launched in 2011 and was not formally released until November 1, 2017. It took nearly seven years before and after it had undergone many discussions. The formal implementation of the new national standard will have an important impact on the entire industry.
    “The revision of this national standard is based on several purposes. It is to meet the demand, quality requirements and safety requirements of the gas industry for cylinder valve products; to further align with ISO international standards and foreign advanced standards; to further improve the existing gas of the country. The harmonization of bottle regulations and safety technical specifications; further standardize the management of LPG valve industry and improve the overall level of valve manufacturing.” Huang Qianghua, secretary general of the National Standardization Technical Committee for Gas Bottles, one of the main drafters of the new national standard, said in an interview.
    It is understood that the "Liquid Gas cylinder valve" national standards were promulgated three times in 1987, 1998 and 2006 respectively. The current GB 7512-2006 "liquefied petroleum gas bottle valve" during the implementation of the national standard, some industry experts proposed revised recommendations. To this end, the National Standards Committee issued a revised task for the standard in 2010. The National Cylinder Standardization Technical Committee was established in February 2011 by relevant industry associations, production companies, inspection and technical agencies, and national quality inspection centers. "Liquefied petroleum gas cylinder valve" national standard revision group.
    It is reported that, compared with the original standard, the new national standard has made important changes in some key and core indicators, of which the more important aspects are, on the valve "pressure resistance of the valve body" requirements, the pressure test pressure from 4 The nominal working pressure is increased to 5 times the nominal working pressure; the valve tightness test method requirements stipulate that under the nominal working pressure, the closed and arbitrarily opened state, and when the pressure is opened under 0.05 MPa, the valve leakage should be Not more than 15cm3/h; Regarding the handwheel's fire resistance and test methods, the ISO 15995 "Cylinder - Manual Liquefied Petroleum Gas Bottle Valve Technical Requirements and Tests" standard is used to stipulate that the handwheel of the valve is at a temperature of 800°C to 1000°C. Burn for 1 min in the flame, you should still be able to manually close the valve.
    In addition, important amendments to the new national standard include the requirement that the self-closing device of the self-closing device should be able to open and close the valve for 1000 times without leakage under the nominal working pressure, and that there should be no leakage. Under the valve temperature range of -40 °C ~ +60 °C should meet the valve's air tightness test requirements, no leakage; on the valve body stress corrosion resistance test requirements, the valve body temperature at 25 °C ± 1 °C, time Ammonia should be stored in ammonia tanks for 4 hours without visible cracks.
    Huang Qianghua said that the revised new national standard reflects the characteristics and advantages of the four aspects. The first is to make the valve structure better. In the old standard, two types of valve outlets are specified with and without a self-closing device. At present, domestic production and use are all structural types without self-closing devices. In the newly promulgated national standard, on the structure of the valve outlet, the structure type of the valve without a self-closing device was deleted, and the type of the valve outlet port structure must be clearly defined with the type of self-closing device. This is the most revised new standard. local. The air outlet self-closing device is a kind of air outlet provided in the valve and can automatically open the valve after connecting with the inflator (or pressure regulator), and can automatically close the valve after the inflator (or pressure regulator) is detached. The protection device, this self-closing device is equivalent to adding an “automatic safety lock” to the bottle valve. It not only learns the structure type of the gas outlet of the foreign LPG cylinder valve, but also fully absorbs several liquefactions that have occurred in recent years. Lessons from the Lessons Learned from the Explosion of a Cylinder in the Explosion of a LPG Cylinder This structural improvement can reduce the liquefied petroleum gas cylinder valve in the process of cylinder transportation and use, such as the accidental opening of the valve handle or improper emergency handling by the user, may lead to the leakage of fire explosion accident, but also to a certain degree of prevention Unscrupulous terrorists randomly open the security incident caused by the valve switch.
    At the same time, the new national standard has higher safety requirements for valves. Mainly reflected in the improvement of the valve body pressure performance requirements; increased valve opening and closing performance requirements in the fully open state; increased temperature resistance and test method requirements; increased hand-wheel fire resistance and test method requirements; The number of valves for each batch stipulated that the number of batches per batch was adjusted to 20,000 and the number of batches was 10,000. It should also be noted that, in order to advance the construction of valve product information traceability systems, the new national standard has also added provisions that the valve must be equipped with an easily-qualified product certification, and the electronic version certification certificate that has been implemented in the liquefied petroleum gas cylinder valve industry must be promoted. system.
    In addition, the new national standards make the standards more operational and applicable. The HPb59-2 material with the same lead content as the internationally used liquefied petroleum gas valve material has been added to the main parts of the valve, and has been further improved on the basis of ensuring the mechanical properties such as the tensile strength and elongation of the material. Valve body material ductility, machinability, wear resistance and other processing performance; based on the traditional water intrusion method to detect the valve airtight, based on the European and American standards commonly used to detect the leakage rate method, an increase of the "hermetic leak" Quantity testing test method requirements to adapt to the application of different testing equipment of different companies, and to promote the application and technological advancement of automated testing equipment of production enterprises; In the design of additional parts, the reference to the provisions of the international standard for adding optional additional functions to the valves , The "In accordance with the needs of users, in line with the relevant regulations and norms of the state, the valve inlet can be additional filling limit device or residual liquid combustion device" provisions to meet the use of the unit's special features of the valve The demand for energy, to a certain extent, meet the needs of energy conservation and emission reduction.
    According to reports, from the current domestic development point of view, China's entire Liquefied Petroleum Gas Valve product quality from a good level in the middle. According to incomplete statistics, each year, China's gas cylinder valve companies produce nearly 30 million bottles and valves according to the National Standard for Liquefied Petroleum Gas Bottle Valves. Some of the company’s national standard products are also exported abroad.
    “After the implementation of the new national standard, all gas cylinder valve manufacturers in China that hold the “Special Equipment Manufacturing License” will produce liquefied petroleum gas cylinder valves in accordance with this standard. The use of cylinder valve products for more than 10 years indicates that the “Liquefied Petroleum Gas "Liquor valve" produced by the national standard of liquefied petroleum gas cylinder valve, the product quality is good, to ensure the safe use of liquefied petroleum gas cylinders." Dr Xu Weipu, director of the National Cylinders Valve Quality Inspection Center, said.
    Xu Weipu said that after the implementation of the new national standard, the adoption of a new structural type of valve in line with international standards will improve the safety performance requirements, will further enhance the quality and safety of China's liquefied petroleum gas cylinder valve industry and related industries, and will further improve the bottle valve industry products. The level of quality and safety will enhance the international competitiveness of China's gas cylinders and valve products; through the use of testing devices for key items specified in the standards, the automation level of product quality inspection in China's bottle valve industry will be further improved to ensure the stability of product quality; Adding the "every valve should be equipped with easy-to-check product certification" provisions will promote the construction of product quality traceability systems for the bottle valve industry. The standard will promote the regular replacement of old bottle valves beyond the designed service life by increasing the “minimum design service life of the valves is not less than one inspection cycle of LPG cylinders”, and enhance the use of liquefied petroleum gas cylinders. Use safety levels.