Glossary of Casting Terminology "V"
|vacuum||A state when the pressure of a gas such as air is extremely low.|
|vacuum gas test||A test in which molten metal is collected with a small ladle and poured into a crucible in a decompression container and covered with a lid. Then, it is decompressed with a vacuum pump to solidify it. A sample is then cut out after cooling to estimate the amount of hydrogen present according to the size and distribution of gas bubbles. Then, comparing the test piece to the master work enables an estimate of the amount of hydrogen gas in the molten metal.|
|valve||A device installed in piping for liquids like water or hydraulic fluid and air for controlling its flow direction, pressure and flow rate. Types include manual and electric valves.|
|vapor proof||Protection of castings from moisture and humidity.|
|ventilation||Actively introducing fresh air into a poorly ventilated place such as a spot with poor airflow.|
|vertical injection||An injection method in casting that injects the molten metal vertically from the bottom of the mold upward in order to prevent the inclusion of oxides, etc., in the casting. However, the mainstream method for die casting machines is horizontal injection.|
|vibrator||A device that generates vibrations to prevent sand and the like from settling in the same location.|