FOREWORD

The more complex industry becomes. the more vital becomes the role played by fluids in the industrial machine. One hundred years ago water was the only important fluid which was conveyed from one point t o another in pipe. Today, almost every conceivable fluid is handled in pipe during its production, processing. tianspoitation, or utilization. The age of atomic energy and rocket power has added fluids such as liquid metals . . . . i.e., sodium, potassium, and bismuth, as well as liquid oxygen, nitrogen, etc. . . . to the list of more common fluids such as oil, water, gases, acids, and liquors that are being transported in pipe today. Nor is the transportation of fluids the only phase of hydraulics which warrants attention now. Hydrzuiic and pneumatic mechanisms are used extensively for the controls of modern aircraft, sea-going vessels, autotnotive equipment, machine tools: earth-moving and road.building machines, and even in scientific laboratory equipnlent where precise control o f fluid flow is required. So extensive are the applications o f hydraulics and fluid mechanics that almost every engineer has found it necessary to familiarize himself with at least the elementary laufs of fluid flow. To satisfy a demand for a simple and practical treatment of !he subject of flow in pipe, Crane Co. published in 1935, a booklet entitled Flow of Fluids and Heat Trarismission. A revised edition on the subject of Flow of Fluids Through Valves, Fittings, and Pipe was published in 1942. Technical Paper No. 410, a completely new edition with an all-new fonnat was introduced in 1957. In T.P. 410, Crane has endeavoured t o present the latest available information on flow of fluids: in summarized fonn with all auxiliary data necessary t o the solution of all but the most unusual fluid flow problems.

The fifteenth printing (1976 edition) presented 3 conceptual change regarding the values of Equivalent Length " L / D and Resistance Co. efficient "li" for valves and fittings relative t o the friction fac!or in pipes. This change had ieiatively minor effect on most problemsdealing with flow conditions that result in Reynolds numbers falling in the turbulent zone. However, for flow in rhelaminar zone, thechange avoided a significant overstatement o f pressure drop. Consistent with the conceptual revision, the resistance t o flow through valves and fittings was expressed in terms o f resistance coefficient "K" instead of equivalent length ' Z / D , and the coverage of valve and fitting types was expanded Fuithei iripoltanr revisions included the up. dating of steam viscosity data, orifice coefficients, and-nozzle coefficients. ? . P 410M was introduced in early 1977 as a metric version of the fifteenth printing of T.P. 4 10. Technicai data, with certain exceptions, are presented in terms of St metric units. Exceptions occur in instances where present units outside the SI syslem (e.g, nominal p i p sizes in inches) are expected to continue in use for a n indefinite period, or wheie agreement has not yet been reached on the specific metric units to be used (as for flow coefficients). Siicccssire printings of T.P. 410M, like T.P. 410, are updated as necessary to reflect iatest flow information available. Arrangement of material is alike in both editions. Theory is presented in Chapters 1 and 2 . . . practical application to flow problems in Chapters 3 and 4 . . of fluids and flow characphysical teristics of valves, fittings, and pipe in Appendix A . . . and conversion units and other useful engineering data in Appendix 3. Most of the data on flow through valves and fittings were obrained by carefully conducted experhenis irl the Crane Engineering Laboratories. Liberal use has been made, however, of' other reliable sources of data on this subject and cue credit has been given these sources in the text. The bibliography of references will provide a source for further study of ihe subject presented.

From 1957 until the present. there have been numerous printings of Technical Paper No. 410. Each successive printing is npd;tIed, as necessary, to reflect the iatert flow information arailable. This conriniial updating. we believe. serves the best interests of the users of this publication.