1 Pore
The image of the pore can be presented on the negative as an isolated or group of round, oval, pear-shaped dark spots, smooth contours, sharp images, the whole image blackness is large, no obvious changes.
2 Sparseness
Sparseness is small, discrete holes distributed throughout the thickness of the casting. The image presented on the negative is related to the thickness of the casting. Thin sections may show up as fine reticulated images; thick sections will show up as faint dark spots, due to the overlapping of the holes. When it is distributed in the central area of the casting, it shows as a blurred dark spot image.
3 Shrinkage and shrinkage
Shrinkage shows up on the negative as an irregularly shaped, darker than background dark spot image with no definite direction of distribution, large area and clear outline.
4 Crackles
Cracks appear on the negative as irregular black lines, which are often undulating and can sometimes form bifurcations.
5 Cold septa
On the negative it appears as a relatively uniform, unvarying, smooth, linear image of black lines or as a flaky image.
Dear Air's valve housing castings are manufactured to meet national requirements for small air separation units, large air separation units and liquid air separation plants.
