Because it ensures precise dimensions, smooth surface finishes, and improved material properties. Cast parts often require grinding to meet tight tolerances, remove surface imperfections, and prepare for coatings or assembly.

Valve metallographic inspection uses a microscope to analyze the microstructure of metals, evaluating features like structure, spheroidization rate, pearlite, ferrite, roughness, and finish to assess material quality and performance.

Spherical content observation analyzes the shape, size, and distribution of spherical features, like graphite nodules in ductile iron, to evaluate material properties such as strength, ductility, and quality.

Hardness testing measures a material's resistance to deformation, reflecting valve quality and manufacturing. It helps detect defects like inclusions or porosity and ensures uniformity and performance.

"Observe the dent" refers to examining a dent on a material's surface to assess its depth, size, and impact on structural integrity or performance. This is often used to evaluate damage or deformation caused by external forces.

Ultrasonic testing uses waves to detect valve leaks. Turbulence from leaks generates ultrasonic signals, which sensors capture and analyze to pinpoint their location.

Detects surface and near-surface defects in valves by applying a magnetic field. Defects create leakage fields that attract magnetic particles, forming visible indications of the flaws.

Penetration detection is a non-destructive testing method used to find surface-opening defects in metal or non-metal components. A special penetrant is applied to the surface, and a developer draws the penetrant from defects to reveal their presence.

A valve spectrometer is a high-precision analytical instrument used to analyze valve materials. Using spectroscopy, it accurately detects elements and their concentrations to ensure the valve's quality and performance.