For the maintenance of infrastructure and the safety of construction workers, and promote the healthy development of valve industry, the State Administration of Quality Supervision recently organized the safety valve for national product quality supervision and spot checks had taken in Shanghai, Zhejiang, Jiangsu, Anhui, Henan other five provinces, 24 municipalities production of 24 products (not related to exports), the products quality sampling rate of 96.3% qualified.
By the sampling According to Recommended national standard GB/T12241-2005 "safety valve General requirements", GB/T12242-2005 "pressure relief device test method", GB/T12243-2005 " Spring Loaded safety valves "requirements, the product of the safety valve shell strength, tightness, set pressure, discharge pressure or more pressure, back pressure or hoist seat pressure, mechanical properties, emission or discharge coefficient, opening height, the valve logo, appearance quality of 10 items was examined. Upon examination, the sampling valve of the shell strength, tightness, set pressure, displacement or displacement coefficient index single line rate of 100%.
Sample found in the main quality problems are: 1. Unsatisfactory mechanical properties of individual products. Mechanical properties is the equipment in the work, the safety valve must be stable, should be no frequency hopping, no chatter, no card blocking and so on. Spot checks in the mechanical properties of individual products appears chatter.

2. Individual product emission or discharge coefficient failure. GB/T12243-2005 " Spring Loaded safety valves "recommended national standards require that the safety valve discharge coefficient should meet or exceed the nameplate specified value.

3. Individual product discharge pressure failed. GB/T12243-2005 "Spring loaded safety valve," a recommended national standard, safety valve discharge pressure should not exceed 1.1 times the set pressure (gas) or 1.2 times the set pressure (fluid). Spot checks in the individual product discharge pressure exceeds the standard requirements, within a specified time can not release the pressure.

4. Unqualified Return Pressure on individual products. GB/T12243-2005 "Spring loaded safety valve," a recommended national standard, the safety valve of the back seat pressure greater than 85% of set pressure (gas), or 80% of set pressure (liquid). Spot checks of individual products back seat pressure not up to standard specified value, the equipment will be discharged from within the media, resulting in energy waste and environmental pollution.

5. To open a high degree of failure of individual products. Open the high-impact safety valve emissions, safety valve in the action, the valve should be opened and increased valve, so as soon as possible to protect the equipment will be pressure within the release time to reduce emissions, help facilities, pipeline safety.

GB/T12243-2005 "Spring loaded safety valve," a recommended national standard, the valve opening height shall be not less than a quarter of the valve throat diameter (gas) or one tenth of the valve throat diameter (liquid). Spot checks of individual products meet the standard opening height requirements.

For sampling the main quality problems identified, the AQSIQ has instructed the quality and technical supervision departments over product quality strictly in accordance with law and other relevant laws and regulations, failure of product quality of the sample companies and the law, the deadline rectification. Meanwhile, good quality spot checks of enterprises, intensify propaganda and guide consumption. AQSIQ will continue to track product quality, safety valve checks to promote safety valve industry, raise the level of overall quality.

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