核级手动截止阀关闭力矩的计算与校核

Calculation and Verification of Closing Torque of Nuclear Manual Globe Valve

手动截止阀具有结构简单、制造与维修方便等优点,因此在核电机组中大量使用。由于核安全的需要,核级手动阀门对密封性提出了更高的要求,而手轮的关闭力矩是影响阀门密封的重要因素,若关闭力不足可能会出现阀门内漏,造成该阀门下游管道超压或者设备损坏。针对这一问题,本文介绍了核级手动截止阀关闭力矩的计算方法,并利用阀杆强度要求对关闭力矩进行校核。为验证该方法的实用性,对某电厂安注系统手动阀门关闭力矩校核计算,结果表明本文提供的方法与阀门厂家给定的关闭力矩存在差异,改进加大阀门关闭力矩后保证了阀门的密封性,同时阀杆强度也可满足要求。

Manual globe valves have the advantages of simple structure,convenient manufacturing and maintenance,so they are widely used in nuclear power units.Due to the need of nuclear safety,nuclear manual valves put forward higher requirements for sealing,and the closing torque of the hand wheel is an important factor affecting the valve seal.If the closing force is insufficient,there may be internal leakage of the valve,resulting in overpressure of the downstream pipeline of the valve or equipment damage.In order to solve this problem,this paper introduces the calculation method of closing torque of nuclear manual globe valve,and uses the strength requirement of valve stem to check the closing torque.In order to verify the practicability of this method,the manual valve closing torque of a safety injection system in a power plant is checked and calculated.The results show that the method provided in this paper is different from the closing torque given by the valve manufacturer.The improved and increased closing torque of the valve can ensure the tightness of the valve,and the strength of the valve stem can also meet the requirements.