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Cross section of constant-volume valve. A micrometer head, MH, is graduated in units of 0.0001”. It moves the spindle, MS, which in turn moves a steel ball, B, a push rod, VP, and the valve stem, VS. The valve cone, VC, was made with an included angle of 58 ° so that it would seal near its tip into a 60 ° seating hole. The stem is made uniform within ±0.00013 mm in diameter in order to ensure constant volume within 0.005 mm3. (Reprinted from reference [13].)
