According to the structural characteristics of the valve casing castings, generally take X-rays or γ-rays as a source of radiation with the technical measures of the way the valve body pressure-bearing parts for radiation detection.
The use of radiation detection technology to detect the valve body pressure parts, you can find internal defects in the casting, to avoid casting defects may lead to valve leakage and lead to deflagration or explosion accidents.
X-ray inspection is often used to detect internal defects in valve castings. The intensity of radiation through the casting is affected by the internal defects in the casting, and the intensity of radiation emitted through the casting varies locally with the size and nature of the defect. The use of film records of defects in the radiographic image is more intuitive reflection of the defect. At present, most valve manufacturers of oxygen valves and cryogenic valve pressure-bearing parts fail to carry out radiographic inspection in accordance with the corresponding valve product standards, then there are defects inside the valve body, leaving hidden dangers to the safe operation of the liquid air separation plant.
Dear air separation to ensure liquid air separation plants, small air separation units and large air separation units oxygen with valves and cryogenic valve pressure-bearing parts and related valve product quality, while the weld, pressurized cast steel parts, pressurized forgings have non-destructive testing requirements.
