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Correlations for Predicting Leakage Through Closed Valves

J. Hord

出版	U.S. National Bureau of Standards, 1967
URL	http://books.google.com.hk/books?id=motKs35pstUC&hl=&source=gbs_api
EBook	FULL_PUBLIC_DOMAIN

註釋

Safety, convenience, and economy often demand the inference of leakage of a given fluid from known leakage of another test fluid across valve seats, welded and threaded fittings, seals, etc.The temperatures of the fluids also may be different. An example is the prediction of gaseous hydrogen leakage at 20°K from test data obtained with nitrogen gas at 77°K. Various flow formulae (molecular, transition, and continuum) are examined, and two simple methods of correlating leakage for single-phase fluids are deduced. The correlations obtained (excluding transition flow through long channels) indicate the leakage is inversely proportional to the square root of the density, or inversely proportional to the absolute viscosity, of the fluid. Thus, for gases, the leakage is directly proportional to the sonic velocity of the gas. The proper relationship must be established by experiment for each valve, fitting, etc.