在核电厂热交换系统中，浮球式疏水阀的阀体腐蚀、泄露会危及核电厂的安全运行。采用微型探头与常规探头结合使用的壁厚超声检测方案，对某核电厂在役浮球式疏水阀的壁厚进行检测，找出了易腐蚀点并计算出腐蚀速率；最后,进行阀体切剖试验，验证了此壁厚检测方案的可行性与有效性。

Float drain valves, which are widely used in heat exchange systems of nuclear power plants, occasionally have corrosion and leakage problems that lead to unsafe and unstable operation. A thickness detection scheme, combining miniature probe with normal probe, was proposed to detect the thickness of the in-service float drain valves in a nuclear power plant, and the related prone corrosion points and corrosion rate were also studied in this paper. Combined with valve cutting experiment, the study reveals that the thickness detection scheme is feasible and effective.